Catchy handle, Thriftmaster! Where'd you come up with that? He, he, he.
Anyway, I have a '48, and luckily, my tank was good. I know there are places that "rebuild" gas tanks - coat the insides and out with some kind of stuff. That might be your best chance at getting a working tank for your '47. In all the years I've been hunting parts for mine I haven't seen a tank for sale.
Bob Adler has a field full of AD trucks, and he might have what you're looking for, but I don't know about the legality of shipping a used gas tank. Here's the website for his place:
http://adlersantiqueautos.com/
