I have bought and eventually sold several rehab projects, which were still flying at the time of purchase, however. In the late nineties to early 2000's it was possible to work under the guidance of an A & P mechanic and perform most of the labor. These were an a E, G, J and K model. I was able to make out fairly well with mostly used avionics upgrades, tank reseal, interior and top overhaul. The J model had a tube replaced by a FAA certified welder due to rust.
Nowadays, there are almost no A & P mechanics who will allow an owner to do this kind of work. I was able to essentially trade my sweat equity and mechanic skills for $ because in all these cases I bought low and sold high.
Like others have said how much do you like restoration projects? It is really satisfying to see an airplane restored to its former glory, but few pilots have the skills, time and desire for a multi year project. For example, good luck finding an engine shop who can find parts to get an engine overhauled. My IA has 5 Moony's on the ramp waiting for an engine, all with 1-2 years delay on engine OH.
Pictures of the project will help fellow mooniacs give you advice, but proceed with caution because you won't be able to discover all the work needed until you dive deep into the airframe. Think of it as a free off restoration of your favorite antique automobile.
Good Luck!