Try contacting Alston Chassisworks for a welded chromemoly back half chassis for your car and see if you can have it installed locally. I had a customer in SO CA years take his 1965 Valaient to them for a back half and later for a front half back when they where working on customers cars Good luck, let us know what you decide
BTW, sometimes it is better, faster and as cheap using a good professional well known shop that builds your car on a chassis jig than a local hack that gets the car into his shop and then jacks the price way up