Here in Iowa I've had Radiator Masters in St. Olaf, IA re-core the original radiators for my 69 Grand Prix and 72 Trans Am and was quite pleased with the results. I'd be very hesitant to ship a radiator these days Bill unless you can make it FedEx proof as njsteve likes to say. My GP had an aftermarket 4 core in it when I bought and when I had the previous owner ship the original to me the core and drivers side inlet were beat up so bad I had to get another tank for it before I could get it re-cored.
https://www.radiatormaster.com/