Original style military 5-gallon jerrycan mounting bracket You can find them lots of other places, too -- most of the military vehicle parts vendors carry them. (Memphis, Midwest, Vintage Power Wagon, etc)
The have provision to mount to either a vertical or horizontal surface. If you mount it to your bed side or running board, make sure its ruggedly secure -- that full jerrycan will weigh approximately 50 lbs or so.
Here's the stock mounting for the jerrycan on my M-37 . My can is actually a toolbox
I'm with the others who say "Sure you can carry gas around in a jerrycan ... but why would you want to?" Mounting it just for the look is about the only good reason I can think of ...:) and having an original Marine Corps can is cool. Is it marked or stamped with Marine Corps markings, then? Do you have a picture??
I wonder if there are others out there, then?? I'd love to have a Marine Corps jerrycan for my M-37 ...