Hello
member of a dying breed here. I've been a camera technician since 1989, and still repair film cameras (in fact that's most of what I do).
Contrary to what people may say you can buy spare parts for most things. One big change in the way things are repaired is that sometimes you have to buy a complete "module" rather than a discreet component, which can make the price of a repair uneconomical.
What do I mean by this? Say something breaks in a lens. Sometimes you have to buy a complete unit (eg aperture unit or IS unit) rather than just replace a aperture blade or broken part in a IS unit. I've seen something as simple as a switch break on a main PCB and rather than replace the switch (which is not available on it's own) you have to replace the whole board.
This is why camera technicians (who are not "factory" technicians) sometimes do "non standard" repairs - things like running jumper cables between 2 pints on a camera flex - rather than replacing the flex, or lapping and relubeing a lens helicoid rather than replacing the unit.
As for repairing film cameras you make do, using second hand parts when available, making non factory adjustments (bending things), or even making replacement parts from scratch (lens guides for example). The frustrating part is when it takes you 1 1/2 hours to get to the part you need to repair only to find the part is broken and no replacement is available. Some people just don't understand if you have a broken aperture blade you can't just put a new rivet in..it broke for a reason, and you need to replace it.
One of the biggest problems today is the foam that was put under the metal bars that hold down the prism's on many cameras. The foam is degrading, and removing the silvering from the prism. And you can't get replacements. Chinese made K1000's are the worst offenders - 1 in 2 would be showing desilvering.
I do agree that it is a dying art. I don't do repairs full time anymore. I have a friend who is 65 and has been repairing cameras all his life. He was factory trained by several manufacturers, and over the years has repaired most brands of camera. (He's also the one who taught me how to repair a Minolta SRT - did you know to do a service properly you need to replace 21 light seals, including some on the back of the mirror box and under the prism!).
We were sitting around a couple of months ago, and he basically asked me to come over and practice repairing things, and he would teach me how to repair pretty much anything he knew how to repair. His reasoning was similar to above - its a dying art, and he is hoping as I'm 14 years younger than him I can keep it going for a little while longer..
Anyway - enough ranting. If you were in Australia I'd be happy to teach you
Cheers
Andrew
PS - how did I learn? I saw an add for a camera technician at Canon, applied, sat a practical test (here's a service manual, here's a camera - pull it apart. After a while they said put it back together. I did that - twice, and got the job. I was there for 5 years, and wanted to learn to repair 120 cameras, so I went to the main professional camera repairers in Melbourne, and learnt Hasselblads and Mamiya, plus leaf shutters and a few other things. Left after a year to run my own custom black and white lab...but that's another story