Corey Feldman -- REUNITED with Famous $100K Jacket

The tacky leather jacket Corey Feldman wore in "Dream a Little Dream" has FINALLY been returned to the actor ... TWO YEARS after someone jacked the $100k item right from under his nose, TMZ has learned.

It's a crazy story ... Corey claims someone snatched the coat while he was hanging out at the House of Blues in L.A. back in 2011 ... and years later, it magically resurfaced at a flea market in Boston.

Turns out, the guy who bought the stolen jacket in Boston realized what he had -- and got in touch with Feldman to return it ... but he wanted something in return.

Feldman was willing to play ball and hammered out the following deal:

-- He flew the guy out from Boston to L.A.
-- He put the guy up at the Andaz Hotel on Sunset Blvd.
-- He gave the guy a 6' female bodyguard to "protect him" during his stay
-- He brought the guy on stage during a rock show in L.A.

Feldman also donated some of the profits from his band's concert to a charity of the jacket-holder's choice ... which turned out to be OneFundBoston.org (which benefits victims of the Boston Marathon bombing).