Radiator shops, in my experience, always put a coat of gloss black rattle can on it just before you pick it up. So you can have some damp paint on your hands...
The 1/79 Pigs came with a fan clutch? I did not know that, i stand corrected.
I am a big fan of re-coring 55 radiators. I've done it 3 times on my Pig. I could never find a new one.
Find the oldest radiator shop in your town.
I think a good re-core is better than new.
Once i tried a 4-core that...
Wasn't '78 the first year to offer AC in a Pig? And they had to slim down the radiator to fit (went from a 3 row core to a 2 row core).
You might be able to re-core to a modern (slimmer) 3 row core.
You're running the larger plastic fan aren't you?