I would replace the old copper radiator with a new aluminum one.
I did this in a B&B about 6 or 7 years ago. Call C G and J inc. a very large radiator factory just across the state line from you in Alabama.
2776 Wills Creek Road
Gadsden, AL 35904
1-800-223-4299
C,G, & J Inc.
I think your radiator is a Ford unit from the early 70's. You will have to give them the dimensions but they will build a radiator that will drop in. I paid $325 for mine.
Buy a fan to mount onto the radiator with a CFM of 2700 to 3,000. Forget the cute little do nothing fans that mount out front.
Dwight