So take this one for example.
http://seattle.craigslist.org/see/cto/4685754768.html
Assuming you don't touch the paint and the interior is good. Talk him down to 18k.
Add fuel injection and an OD trans
RideTech bolt ons
Same rims, new tires to match the new height
Nice vintage muscle that looks and drives better than new, nothing crazy and can be put back to stock. Average dude at the local XXX having fun and getting the looks.
What's it worth?