OK, first the heater. Bill is correct about destroying the fan blade. I was able to get the heater motor and fan from Moss. TRF has them listed, but didn't have any in August. That may have changed by now.
I don't think that the squirrel cage ever went anywhere.
Please do yourself a favor and have the core at least checked by a good radiator shop. If any doubts, now is the time to replace it. Also, get the new hoses for inside the car as well as the connector pipes to the hoses on the engine side of the car. There is a seal that you want to get for that as well.
Ebay blower motors are very iffy and if you compare the price between a new with warranty, versus 30+ years old, it's no less expensive to buy new, considering the labor to pull it out. And TEST it BEFORE you install it.
Erik is a good friend and does all of the work that my old sore back will not allow me to do. He is the best that I've ever known for these cars.
My car was not recently painted, just the engine compartment, trunk and door jambs. The paint was redone in 1985 because of fading and the job was great on the outside, but the painter didn't do the above mentioned detail areas. I had no rust, just faded paint and wanted to improve the looks of the car.
Every paint job is different depending on the condition of the car as well as the type of job that you want done. I would recommend Alan at A&E in Pawtucket. he is the only guy that works on mine, as you can see from the site. There are others that are good, but not a mile and a half away from me. Besides, he's a good friend and I trust him completely. His shop is spotless and he is fussy as can be. Drive it up and get an estimate.