Bob, not sure if this is the same as a ’51 but this is a 1950 that I just finished wrestling with. The first tank was from Classic Parts of America and it was an “Off Shore” misfit SOB that didn’t line up, had a straight metric thread in the outlet and did not have the flanges formed for the strap saddle.
On Ken’s advice we bought a Spectra Premium Ind. Fuel tank thru Tanks-to-Pans and it was made, lined up and fit just like the original tank. Here are a few pictures of the project. There are also two pictures of the original fuel shut off as it would have been on the 1950 model AD.
http://www.pbase.com/dennygraham/larrys_1950_3100 Denny Graham
Sandwich, IL
