What Brandon said. Why "reinvent the wheel" trying to find parts for a saw that should be retired. Find a more modern saw with good parts availability and you will be a happier camper. I've kind of lost my "thing" for really old iron. Too much time looking for parts, too much vibration to run, heavy, and slow. That said, they sound great, and are fun to play with, but I wouldn't be too keen on depending on one for work.
Mark
+1 Brandon and Mark said it well. Theres a reason the big Stihls and Huskys have replaced the old iron. The old saws are fun to run once in ahile if you're into nostalgia but if I have to pack something in the brush all day and then find parts for it later I'll stick with something modern.