The white wheel is not unknown, but was not offered as a listed option or service part, so it was either a factory special for display at a show, or more likely a dealer special arrangement.
The setscrews in my Mark V (same wheel) gave me the excuse to buy an impact screwdriver.
BTW in case you didn’t know, your knurled nut used to have a plastic covering that said Bluemels on it.
White steering wheels were a listed option for XK120, but no idea how common/rare they are.
See attached pic of a local car with a race history in Australia, gradually being returned to a more trcatable road specification - but steering wheel is its original with ‘period’ lightening modification, not fixed when wheel was restored.
I looked through all the XK120 sales literature I could find, and I don’t like to contradict Roger, so I think a couple of possibilities are at work here. He may be remembering the optional Brooklands wheel, listed in the SPC as being 16" though mine measures 17" at the OD. Or more likely, he may have access to a sales brochure I haven’t seen.
My regular 120 wheel also measures 17" OD.
My Mark V wheel measures 18", and it is interesting to note that the XK100/120 wheel was quoted as 18" in the initial Advanced Particulars brochure.
The early color brochures show a tan wheel.
Mitch, can you measure the diameter of your white wheel at the outside?
I notice a nut holding the wheel onto the column - different column and wheel hub, different part numbers. I can’t imagine they would offer the 140 wheel in white if the 120’s white wheel didn’t sell at least well enough to make a dent in the stats.
I give up for now, as after a quick look for my reference, it wasn’t where I thought it was - in the SALESMAN’S DATA BOOK for the Mark VII and XK.120 MODELS (1st January 1954).
I do distinctly recall seeing a period reference to XK120 having optional White Steering Wheels, but was not a main-stream reference such as the SPC nor the common Sales Brochures. My secondary references are unfortunately not well indexed - one day maybe
So unless someone else with better memory than mine, and with a good collection of period XK120 literature, can advise … I just don’t have time/priority to look further.