I always thought a resurfacing of the flywheel without cleaning up rivet scoring so would only remove .010" each time it was done. Can't imagine with rivet scoring it would be a whole lot more unless done numerous times, or by a hack in the back room.
There are shims available in varying thicknesses. Check Rock Auto, Summit, or your local speed shop.
[This message has been edited by Kevin87FieroGT (edited 06-25-2014).]