Does anyone have a vendor contact for radiator repair? I think mine is brass. It's the original from 1930.

It is quite a distance from Illinois but The Brass Works in Paso Robles CA does great work. Or you could check with the VCCA region near you for a recommendation. You would think with all the old farm equipment in that area there would be someone who has a quality shop. So maybe check with a tractor club. In Vancouver WA I use Wilson Radiator. They will repair an older unit if it is not too thin and brittle.

Make sure and stress to not pressure test it with more than 2 psi. I heard of a moron in a shop who put 12 psi in it and it was then not savable. These are non pressure systems.

There is a radiator shop in DeWitt, Iowa that might be able to repair it. Expect to wait a long time and pay good money for great work.