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.
Also, they checked their records going back 3 years, or so, and have found that out of over 90 sold that there was only one returned radiator; that one returned due to damage. The radiators are made in the USA by a company that only builds radiators. The description in the catalog is based on the specifications provided by the reseller to the manufacturer, and the expectation that the manufacturing process is being done to spec.
Perhaps "my" radiator was a one-off production defect; the sales/return/complaint ratio would seem to indicate that. I suspect that there will be heightened scrutiny of the quality control process from their supplier also.
Needless to say, this vendor continues to be one of my favorites and I will, of course, continue doing business with them. They truly are great folks and provide tremendous support to this site.
Don
