I get aluminum ones from Ebay for $200 delivered. The top tank is shaped very much like the original brass ones. That is how I know that it is the right one. (I can never remember who sells them.) I prime the tank and sides with self-etching primer and paint with Rustoleum Gloss black. You have to know what to look for to pick it off as not original.

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission