I dont wish to jump down your neck Lee because there has obviously been some miscommunication between you and Neil. I admire your fastidious approach to your vintage Yokomo restorations too
You cant be complaining that it has turned up gold though. Its not to my taste either but i think that comment was a bit unfair. It was gold when you first laid eyes on it.
Its a used car, the diffs and shafts dont look knackered to me from what i can see of them. New unused is very different to newly replaced. You see full sized cars listed with new brakes, new tyres etc. That doesnt mean that the wheels havent turned since they were fitted, it means that you wont need to replace them in the near future. Clearly there was bad understanding between you guys or your expectations exceeded what is reasonable when purchasing a used model. Maybe would have been best to hold out for someone selling a NIB one, they do come up from time to time.
Best wishes