Hello Alan, thanks. The Bearing and Pinion surfaces at each end cleaned up ok with no pitting, even though the L/H Drive Chain, Sprocket were solid with rust and the R/H Bearing rusted up.
Checked them over with a Micrometer , then polished them up with Crocus Grade Emery. Bearings are still a press fit. I had made covers for these areas out of Copper and Brass tube to protect them at the Blasters.
The Drive Pinions are less worn than my originals (they were subjected to sandy soil lawns in their previous useful life, but all still good/useable).
So it means I can use all the Drive parts from John's Donor Mower including the Wheels as the parts all have 'Bed In and Mate Up' well together.