Ian,
Most of the vintage re-builders/restoration folks take into consideration "The Hunting" part of the job as much of a challenge as getting the mechanicle work done. here are a few places that sell carb parts. I don't have any personal recomendations so shop around.
I have found that bikes over 10yrs old the parts are not only tougher to find, the cost starts going up. Once the manufacturers exhaust the production run of a part, they will contract a smaller outfit to make batches or units and it usually goes out for a bid.
The Manufacturers are gonna make money on the part as well as the subcontractor. The dealers usually have a part# cross reference to see what else a part was used on. sometimes that will help if your looking for say an axel bolt for your '83 but the dealer says the part is NLA no longer avail. if that so happens to fit a 2000 ttr125 your in luck... (Just an example of coures) snoop around the net for some more restoration ideas and I'm sure you will find some more help.
One more tidbit on the carb. Once you gather up the prices on what your looking for to re-build the carb,
don't be too surprised if it will be comperable to getting a new carb when figuring in all the shipping and tax etc.
The price of a new slide is around $70.00 alone. When I re-built my '85 Cr 500 I had replaced everything but the carb body....well when I just couldn't figure out what was going on, I ordered a new Keihin PJ and ended up spending a half more than just replacing the whole thing to begin with. The carb body itself was worn and letting air around the slide...
Tuck\o/
http://www.motorcyclecarbs.com/ http://www.sudco.com/http://carbkitscapital.com/http://www.oldbikebarn.com/Motorcycle_Parts/Carburetor
