Hello, Mr. Barton. Might this be your truck shown on flickr?...
http://www.flickr.com/photos/94957089@N00/3638546153/in/set-72157619932853868/Wish I could help out with some photos but I lack shots of the forties era tankers. To my knowledge, the cabs would have the truck number painted on the door just below the window (ex; No. 286) and maybe Gilmore Oil Co on the front bumper. Checker flags with one of two-types of lion designs in the center were mounted on both sides of the cab. The tanks would have Gilmore on both sides and from what I recall- Gilmore Record Breaker or maybe Gilmore Red Lion on the back of tank (doors). I have also seen them without anything on the back. I'd try contacting the AF Gilmore archivist who works at the Farmer's Market in Los Angeles. They'd likely have several shots/angles of forties era tankers.
I'll look through some paper stuff to see if I am forgetting an image I might have. The photographs I have from this era are mainly custom tankers that were for show and never were transport trucks.
Good luck and post pics of the progress!
Here's one like your truck...
Neon tubed tanker...
Streamliner...