As
@Ghost95 said, DIY is the best approach... Both financially and so you truly understand your gear.
If the hose loop isn't usable, that's going to be the biggest single cost (about $100 total between mouthpiece and hoses), but it could be good... One of my favorite hose loops is an old original one.
The C-clips holding the cans together are a pain, so I highly recommend buying a band clamp for it ($25 last I checked).
Internal soft goods are easy... 1st stage is parts interchangeable with a Conshelf inside, and second stage takes the same basic hockey puck seat as a Conshelf or countless other unbalanced second stages.
Main diaphragm is the biggest question mark... If it's good, it will still be stiffer than a new silicone one, and the tabbed ones are sometimes harder to find. A good shape original is still dive-able, just not as responsive as new silicone.
If you want accessories (octo, BCD hose) there are a couple of cheap ways to feed those off the hookah port.
The repair manual is available in the catalogs and manuals link at the bottom of the VDH site:
They also have parts (when the store is up) and the forum has oodles of great info.
Another good parts source is The Scuba Museum:
And another great forum for vintage gear is at:
Visit our forum at: vintagescuba.proboards.com
vintagescuba.proboards.com
Respectfully,
James