I used sharpened brass cartridge cases as gasket cutters, at least until I found a very nice set of gasket punches from MAC tools (used) on Ebay for a killer price. The trick for getting a clean-cut hole when using a gasket punch is to back up the piece youre cutting with something like a block of red oak or hard maple.
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!