Heck, get it from Marlin! it's on sale....
I bought the OEM rebuild kit for $55. Marlin has the MC and reservoir on sale for $109..... that's killer!
http://www.marlincrawler.com/htm/brakes/mcylinder.htm
how much is it from the jy? jy part + rebuild kit < New
trying to get a few extras for "cheeper" these days