It's a royal pain in the butt to do so, but stainless steel shim stock is available in various thicknesses on Ebay, and some time spent with a small, very sharp set of tin snips can result in some home-brewed shims. Cutting out the inside diameter is the tricky part!
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!