Not knowing how much of a project you're looking for, take a look at one of the Dynaco Stereo 70 kits, which are updated and improved. I'm currently assembling a version of this amplifier, which I bought on Ebay, also available from (tubes4hifi.com). The parts and assembly instructions are of high quality, and has been a good winter project for me. Buying an old unit for updating sounds like a real PITA, and who knows what you'll end up with. The XFMRs, components, and driver board are of higher quality in this kit, and resolve known problems with the originals. The chassis is an attractive polished stainless steel too.
Good Luck.
Howard
Good Luck.
Howard