C 42072 adaptor puzzle

That item is at the back of the V, bolted to 2 pillars cast into the jackshaft cover. You bolt the cam oil feed pipe to the adaptor.
So I spent an hour hunting around the factory where I have the V12 being rebuilt, looking for the adaptor that I must have removed from the engine. I have found all the other bits and pieces but not the adaptor.
At home in the garage I found an adaptor in a box of spares. Most of the spares came from an old pre HE given to me for removing bits I might need one day. That made my day until It came time to bolt it onto the engine.
Much to my consternation it does not fit. The tapped holes in the cover are on a 54mm pitch, the holes in the adaptor are 63mm pitch. Fail to see a reason why the jackshaft cover was presumably changed, unless the adaptor is an orphan from another engine.

The engine number is 8S59277SA which I guess is about mid 80s.
The adaptor has a part number cast into it: P37663A ADC2.
Can anybody please put me wise ?

this seems weird, as the part number seems to be the same for all XJS versions, and XJ too

https://parts.jaguarlandroverclassic.com/c42072-banjo-adaptor.html
[ Part Applicability ]
[SERIES III SALOON 1979 - 1992 CLASSIC]
[XJ 1995 - 1997 (From 720125 to 812255) CLASSIC]
[XJ6 & XJ12 1987 - 1994 CLASSIC](
[XJS SPORTS COUPE/CONVERTIBLE 1975 - 1996 CLASSIC]

there could have be a change in the block top cover , as there are several parts
C39655 (5.3 V12)
EBC9399 (6.0 V12)
NAB1213AA (6.0 V12)

but all list the same part, ie C4072

You cannot reliably use the Part Applicability list. It is an indication that it was used across different Jaguar models, but the date range is just part of the title of the top level of each model hierarchy. If you picked a part that was only for a 6.0L, then it would still list all of [XJS SPORTS COUPE/CONVERTIBLE 1975 - 1996 CLASSIC] as being applicable.

I have one if you need it.
Stephen

yes, I noticed that but went to each XJS model page for the block top cover, from the model /year search
the model in parenthesis come from there : the top block cover changed from 5…3 to 6.0 , then again in the 6.0, but the bajo adapter stayed the same : C42072

I would be surprised if C42072 changed.
Why spend money to alter the design ?
It mounts on two pillars on the jackshaft cover which are not in the way of anything else.
So even if the cover had changes made no need to alter the pillars.

I guess the adaptor I found in my home garage is not the genuine item. It did not come off the engine being rebuilt. I will have one more attempt to find the adaptor that must be hiding somewhere.