Just for inspiration here is a 1938 Dodge Airflow Tanker at the Henry Ford Museum. The Walter P. Chrysler Museum has one too. The one at the Walter P. Chrysler Museum was quite expensive to restore . . . rumored to be $100K. I believe that Texaco paid part of the restoration costs. The one at Henry Ford may not have been quite that much as it was done 20+ years ago I think.

And here is an odd Dodge tanker (1936?) that has a standard cab and an airflow tank that somebody found and hauled home. So they are out there you just have to find them.

It would be great to find a fat fender with streamlined tank.