Okay -- here's the scoop from the vendor. They have generously offered me a parts credit for the faulty radiator, or a replacement--my choice.
Thanks for the update. Your supplier is also my preferred vendor, and that's not going to change. They have always treated me well. Nevertheless, I'll proceed with a lot of caution. While a lack of solder may be a one-off problem, thin material isn't. I would be buying a different radiator than you (my truck is a 1952 GMC), but the problem may be the same. I learned a lot from this discussion, thanks.
