Would it not have been cheaper to buy another one?
That's missing the point!
I'm presently making arrangements for my older Land Rover (a 1964 SWB) to be rebuilt with a new galvanised chassis. I'm well aware it will cost several times the value of the car, but it means that when my present Landie needs replaced I will have the next one waiting.
The same thing applies to Grey Ferguson tractors - the cost of a rebuild will exceed the market value, but sentiment justifies the cost.
I suspect that every vintage or classic vehicle in existence has had more than it's value spent on it at some time, just to keep it going through the point where it's value was negligible. If nobody did this, there would be no historic vehicles at all. The same is true for good furniture - most antiques that are a couple of hundred years old will have had expensive repairs or restorations done, probably at a time when their relative value was quite low. Certainly my great-grandfather's barometer has had some of it's inlay replaced within my memory, to keep it looking as the maker intended, and my parent's furniture has been recovered as required.
John