The end plates are cast aluminum, and a pretty crappy alloy at that. Yes, they can be welded- - - -find somebody who is an artiste with a TIG welding machine, and pay him about three times what you'd spend on a "rebuildable core" generator on Ebay. The job won't be easy, and anyone capable of doing it right should be charging premium prices for his work.
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!