A correction, then, to my previous post. Cap-A Radiator in Farmingdale, NY was acquired in 2023 by Acme Radiator in Islip Terrace, NY:
https://acmeradiator.net
49 Carleton Avenue
Islip Terrace, New York 11752
631-581-9199
I just dropped my '56 Safari radiator there on Monday to be re-cored, and they tested my heater core for me (which, amazingly, was good).
Hopefully, this will make its way into the "next" update to the master list. ;-)