Wilmot Breeden Union Key Series

Has anyone done a study on when, i.e. what years, the different key series letters were used?
I have FA, FP, FNR, and MRN.
Some with one numeral digit, some with two, and some with three.

As far as I know (or think I know) the SS Jaguars both coachbuilt and all steel used Bilfix locks and the MkIVs used FNR series. I suspect MY1940 cars also used FNR series

MRN numbering generates the same saw tooth profiles as FNR but it has different a different side profile.

FA and FP are later series.


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I have done a lot of Jaguar Keys, as part of what I provided in my JAGUAR XK140 EXPLORED book (co-authored with Bernard Viart who did the illustrations).
But given nothing had ever been done before on KEYS I extended my coverage to all the range of WILMOT BREEDEN keys, not just those related to XK140, so includes MRN and FNR series as well as FA, FP and FS…

The letter code denotes the PROFILE of the Key, which I measured up and sketched as follows…

WB-KeyProfiles.pdf (41.5 KB)

Within XK140 EXPLORED, my sketches have been drawn up somewhat nicer, and indeed also with drawings of the actual keys. But once you select your KEY BLANK PROFILE then a range of different profile TEETH are cut into the blank, and are identified by the suffix number, with a range of TEETH PROFILES were available for each of the different KEY BLANK PROFILES as per following…

MRN 1 to MRN 50
FNR 1 to FNR 25
FA 501 to FA 625
FP 626 to FP 750
FS 876 to FS 955

In XK140 EXPLORED I also go into the three different HEAD Shapes that for an owner allowed easy identification of which key was for Ignition, Boot, Petrol Filler Lid etc, and indeed as you do, have acquired quite a collection of original Keys over the yeras, albeit there are a few on-line vendors of original Wilmot Breeden Keys, as well as the regular Swap Meet finds (at least still so in Australia).

Good luck…


IIRC Jaguar only used 8 different keys for the door, trunk, fuel filler and ignition lock on the MKIV, the MKV and early XK120. FNR14 to FNR21.

On the MKV the passenger side glove box lid has a short lock barrell which is some completely different type, mine has number 14 on it.


PS. Interesting to know Jaguar already with the XK140 had the ”valet key” idea where the trunk could not be opened with the same key as the doors and ignition. AFAIK on the MKV the key head was round. On the much later E-types both key heads for the WB keys are rounded rectangle, at least on two European sold cars with WASO ignition and steering lock that has a black plastic key head, just like European sold XJ’s too (1968-1978). Those E-types are from 1967 (German/Swiss market) and 1972 (Belgium).

How about MKVII?

Getting a little off topic but my detailed coverage of KEYS in XK140 EXPLORED was of course specifically aimed at XK140, and indeed notes that virtually all XK140 used only FNR and FA series keys, albeit some of the very last may well have introduced the next FP series keys as found in XK150s. FS Keys didn’t appear until the 1960s, and indeed were the dominant key, noting that if the optional WASO brand steering lock was fitted, then of course you did not get the British made Wilmot-Breeden normal key, but instead got a German made WASO key. This WASO steering lock was offered initially on German market cars, and extremely rarely on USA market cars, with current research saying rarely fitted to both E-types and Saloons from September 1962 onwards, but good luck finding any such early cars such as a 3.8 E-type so fitted…
The new car literature pack of E-types/Saloons so optioned did include an insert within the Handbook describing the WASO steering lock, indeed the first version of this insert was in dual English/German language, albeit from 1964 onwards the second version of the insert was in English only…

See attached photo of a 3.8 E-type Literature Pack that I have, that includes the WASO steering lock insert - in dual English/German language, being from a July 1963 E-type roadster for the USA market, but a ‘Home Delivery’, so good chance of being German based US Military/Embassy…(I should check JDHT)

But back to topic…
Which Wilmot Breeden Key Codes were used in Mark IV/Mark V - I will leave that up to those who claim greater expertise than me - I have never really taken notice apart from presumably MRN dominated ???, but will still be of PROFILE that I have shown, and in range MRN 1 to MRN 50 being all that was made…

The was a guy here in UK called Peter Weston, (unfortunately he died 3 or 4 years ago). He was known as Lockman, and wrote monthly articals for a classic newspaper. Having worked for Wilmot Breeden for many years he knew all there was to know about his subject.
He also wrote an interesting book which will answer all your questions.
I’ll see if I can find some details about it.

My goodness! I hadn’t realised that Peter Weston had died. His articles are still being reproduced in Classic Motor Monthly. I hadn’t read them recently and failed to spot the header noting his death in January 2017.


Peter Weston’s book titled “On Virtually Every British Car” is mentioned in the obituary at https://www.classicmotor.co.uk/news/peter-weston-cmm’s-lock-man-has-died

Hi Roger,

Yes, that’s all very true. I think Germany and Sweden were the first European countries to demand steering locks, ban winged spinners and protruding things like leapers etc ca. 1965.

Thus the 1967 PED car I mentioned (destined for Switzerland and later Finland) had “German spinners” and the WASO steering lock.

I think the reason one of those might have ended up in USA is thst they were either PED in Europe first or just a change of destination that happened on the assembly line. We have at least two 1965 E-types that were delivered new in Finland and had the special front indicator lenses required in here back then AND a 3:51 final drive plus the Lucas hazard system which to me means they were US spec cars that then just had the front and rear lenses changed and were shipped to Finland.

But also back on topic, I don’t have the source now at hand but it must have been a Jaguar bulletin or addendum to spare parts catalogue stating that the keys for MKV and (at the time) XK120 were “FNR14 to FNR21”.

I’ll try to find it.


Great information, chaps.
My '38 SS has 3 different FNR keys, ignition door and boot, which given I have never heard anyone speak fondly of the Bilfix keys, makes me conclude some PO changed them all, either in the Mark IV-V period or from a donor of that period.
My Mark V has FNR door and boot which appear to be original, and FP ignition, but I found a burned wire in the instrument panel harness, which would have gone to the ign switch, so I am inclined to think the original switch was burned, the reason for this investigation, and has been changed to the FP.
My 120 has FAs which appear to be original.
No clue on the origin of the MRN.

A PO has certainly changed the boot lid handle on your car Rob for a MkIV/V type so no surprise about FNR there. When I first got my car the ignition lock was FNR (and still is) but the boot and driver’s door were still Bilfix. The problem with the Bilfix locks is their fragility and unobtainable keys. Fortunately I discovered that modern remake boot and door handles were available and designed for modern lock barrels.


Hi Rob,

On my DHC #647194 one key, FNR14 operates everything else but the glove box. Despite the hack done to the wiring looms most likely in the 1970’s I have no reason to believe any of the lock barrels were changed, except the door handles, which were non-original (one without a lock barrel, most likely from a MKIV).

But the ignition switch, the boot lid handle and the fuel filler lock barrels all show “FNR14” on the front, which must have been very handy for the old school car thief as you didn’t even need to try different keys if you had those eight FNR keys with you. :slight_smile:



IIRC your 120 is a FHC and from 1952? So the change from FNR to FA may have happened around the same time as the MKV production ended (summer of 1951) and the factory moved to Browns Lane. I don’t know if early MKVII’s used FNR, I think in 1952 MKVII’s also had FA keys. Then later came FP followed by FS etc.

I have no idea when MRN was used and why. Also Jaguar changed the glove box lid lock to a bit deeper mechanism so they could use similar lock barrels there.

Anyone know if any other models used the same or similar small lock barrel in the glove box lid lock (BD.2504) as the MKV? Was there a similar one already in MKIV and SS Jaguars? I have not seen it in any others, but again of course at Stoneleigh etc. my eyes are always focused on MKV and E-type parts. :slight_smile:


PS. Correcting myself, I just saw from your profile that your XK120 FHC is from 1951, but perhaps built after June 1951?

Yes, my 120 is Nov '51.
The Mark V and a few very early 120 FHCs (to 679093, not mine) used a Tudor lock in the glove box aka cubby box.

I took my lock to a lock place and found a key blank that would insert, then had them cut the shape from my Tudor key so I have a spare.

Hi Rob,

Thanks, ”Tudor”, that’s it! I have two functioning locks with keys made the same way. :wink:

I think both have the letter ”T” and some number ”9” or something stamped on the front face.


Might need a whole new thread for Tudor lock markings. :grin:
Mine has T14 on the lock and T7 on the key but it works.


Yes, well 14 is two times 7. :slight_smile:

I have told this before, but I once to the subway to where we had a garage with four other enthusiasts and I was intending to go cruising but notice I hadn’t taken the car keys with me. bun in my pockets I had a bunch of keys most of which were for simple bicycle locks, these cheap closed loops we use to lock bikes, soooo I tried and I think not the first nor the second, but the third key worked well for the ignition lock and off I drove! :smiley:

PS. As your “14” is facing that way, mine could as well be “6” or “66” but I think the other digit is a “ghost” that happened easily when they were doing the stamping. So I take it it’s a nine “9”. I think I now have a Jimi Hendrix song coming off the back of my head…“If Six Was Nine”. :slight_smile:

I have another Tudor lock, T28, same orientation as the T14, so I think it slightly more likely that yours is T66 rather than T99, although not particularly useful information unless we had a locksmith with Tudor codes. :smile:


Oh, what do you know, I think you’re prefectly right. :slight_smile:

I thought the other digit was a ghost, which I have seen on engine blocks etc where the punch must have bounced a bit. So it probably is T66, and I have two keys that work. :smiley:

Curiosity snuck up and bit me again, so here is what’s inside the Tudor T28 cubby box lock.

The pin has a very slight curve to hold it in place.
I’ll take it to a lock smith and see if they will make a key for it.