For those of you that missed it, he said that it has been converted to R134 years ago.
The system can be fixed as long as parts can still be found which it sounds like they can be. You definitely need gauges and a vacuum pump at the minimum and a can tap if using 12 oz cans to refill with.
I've kept the AC in my 92 Cavalier working up until recently when I discovered that I have a leak somewhere since my compressor wouldn't come on and I only had about 10 psi of pressure on both sides. I still have a partial 50lb tank of R12 so I've kept using that in this car.
This is a good auto AC forum where I learned a lot about AC repair. You can also ask questions and there are a lot of knowledgeable people in the forum.