Success on the pivot shaft:
Some careful sawing and using a vice to hold the puller slowly released the last bits from the pivot shaft.
On the other hand, trying to pull the stub axle from its carrier broke my puller:
Oops! I then took the carrier to the local garage where their press quickly persuaded the stub axle to come out. I must get me one of those too!
All the donor parts are now disassembled, so the reconditioning of the diff is next. I ordered the gasket and a replacement pinion seal, let’s hope that is all that is needed.