Was thinking of keeping it and sending it in for repair but I learned my lesson many years when I got an old F1n and found out it was a unrepairable.
I would like to have a word with your technician...
It is very difficult to think that a F1n (original F1, improved model) could be unrepairable.
Once, i saw an ad for two F-1 cameras and i immediately went to see. The two cameras were in really BAD shape; basically one of them fell into a river and got soaked, and in the other one something even worst happened:
This guy, photographer, had two little kids around the house and one of them found entertaining to poke the F-1 shutter curtain with a pen or some similar device. And he trashed the shutter curtains.
This photographer send them to service and the repairman, instead of replacing the curtains, did patch them (how, i don't know and it's still something that I would like to know!). The curtains looked really kinked and with black patches on the repair points. Really, the curtains looked horrible, the ugliest curtains i've ever seen.
So at this point in time i was disappointed that the cameras were in such bad shape... BUT... BUT... BUT...
... They worked!! I would guess speeds over 1/125 were not accurate at all, but the cameras did work.
So any repairman that would come to me and tell my a F-1 is "unrepairable", i'd guess that's just BS. On the other hand if it was a
New F-1, which relies on electronics for triggering the shutter, and the electronics were dead with no spares, then I would understand.
Maybe this is because in my country a really
good repairman is considered one that actually repairs stuff, not just replace a spare part with a new one. Here, when a good technician sees something not working, he'll try to make it work first.