I did some research into shift knobs a few weeks ago (want to make an adapter kit for older auto boxes to take newer shift knobs). That looks like an early shift knob, like pre-95. The newer ones have a twist-base to unlock and leave an exposed shaft, some slightly earlier ones have a two-piece shaft and knob and the really early ones (126/124/early 202 etc) have the one-piece shaft and knob.
Hard to keep a straight face with all the shaft and knob talk!
Sometime between 1993-1995 the shaft became 2-piece and if you can get hold of the y-shaped piece where it attaches to the shift mechanism you might be able to adapt the whole thing to the newer auto box.
What we really need is for everyone to state the model/year of car they own and the type of shift knob it has. We should be able to track down the parts needed to swap shift knobs between models of different years.
EDIT: some of the parts are peanuts too, like under £10 for all the bits.