Paul, Under the adjacent heading of steering wheel restoration there is a photo of the inner part of the hub which gives some idea of the key arrangement. Hope this is of some help.
Thanks for the info. I had seen a steering wheel at Beltring that seemed to be the correct black one, but......it was splined ans since I have never had mine off and the manual is a bit lacking in this type detail.
So in reference to the one I saw at Beltring, on another thread here someone mentioned that they believe the splined one is for the 5 ton 800 series trucks. It would seem it is possible to mod if you taper it 7/8 to 1" and add keyway as they are the same other than that to the early Scout car steering wheel.