Unless you are going for an authentic restoration, it may not be worth messing with. If the stock system uses that York compressor, and I think it does, it will be amazing if it is functional. Even rebuilt units, we have gone through three replacement units on two different cars- that's three each. Maybe we just got the bad batch.
If everything is in good shape, condensor not clogged, etc, then you will need R-12 to get good cooling, which is expensive, and if you put R134 in it, which way less expensive, the efficiency will be average. I would bet, by the time you are done, you will have at least half what a CLassic Auto Air replacement system would cost you, and they blow ice cold air.
THe least it will cost you is the R134 to charge it, assuming the compressor doesen't leak, the condensor is not clogged, the evaporater and expansion valve are in good shape.
Not trying to sound like a killjoy, just make sure you know what you are geting into with an original eq A/C system. And before you are a bunch of money into it.
It would be good to know if the parts car system is still holds a charge. If it does, than you have a pretty good chance of getting it to work fairly inexpensively.
