Find an old pressurized-water fire extinguisher to use as a canister. I remember seeing them in the hallways of the high school where I taught for 20-something years. They're obsolete now, but you might find one around a scrap metal yard. They're polished stainless steel about 8" in diameter and heavy duty enough to be durable when mounted outboard on the cowl. With a little tinkering you should be able to make a pretty presentable air filter housing.

Edit: Several on Ebay right now, at good prices.
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!