Steve, check your private messages- - - -the little flashing envelope icon at the top of the page. One work-around might be a fuel cell like the road racers use. They come in all sorts of sizes, shapes, and capacities, and with a little creative bracketing you should be able to fit one to the space you have available. Most fuel cells are made of a flexible rubber or plastic bladder tank, inside a sheet metal housing.
Have fun!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!