Update: I was able to remove the new seals easily with gentle and judicious means, and have cleaned up all surfaces to remove any proud bits, and in general - cleaned
up the prop shaft as per guidance (light emery paper, shoe-shine style,
to remove build-up and scoring), and the internal bore of the pressing fitting
(within which the prop shaft sits).
I also made a v.light emery on the inside bore of the NEW wearing-out bushing (the one that would not fit on the prop shaft).
The new bushing can now be 'wound' onto the prop shaft using hand force only (albeit with no O-ring fitted). The new (SKF) lip-seals fit comfortably on the (new) bushing, and seem to be able to be fit nicely inside the bore. So, hopefully, I will not need to resort to re-using the old wear-bearing with speedi-sleeves.
Today: lube-up and re-fit the new lip-seals and wear-bushing, and then put prop back on.
Note to self: in a warm glow of self-accomplishment (and hopefully with help from Vladamir), don't forget the oil (80W-90) for the C-Drive !!!