just got a cool old bike with a cool old shimano deore biopace crank. i found a bolt for the granny ring was missing. i took out one of the other bolts, and headed to the hardware shop to look for a replacement. couldn't find one. rode home, tried to replace the one bolt into the hole that'd been empty, and it's stripped. i really want to keep the cranks, b/c they're cool. have i any cheap way of saving this crank? helicoil kits are $40, and i've never used one; i worry that i'd eff it up. should i get a NOS crank? A set of sugino xd crank arms? or is there a cheap way to keep the oe crankset?