A Muncie without a shift plate, and with a trashed cluster gear and at least one output gear damaged is just one step above a boat anchor. If you decide to repair it, have it completely disassembled, and check the case closely for cracks. They're not the world's strongest design, and one that's been hand grenaded is likely to have some hidden problems, too.
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!