need some help, rear master cylinder needs rebuild, that top washer is frozen in there, busted out the circlip, got penetrating oil sittin on it, any ideas? also where to get rebuild kit--found a bunch on ebay--i guess pick 1---poke n hope, some seem to have more parts, some look like a black plastic piston rather than steel? maybe just generic pics? if anyone has a link i like to get this ordered tonite