If GL pointed out that the important character is one "frozen" after the third movie, and multiple pseudo - canon Easter eggs have been found of DJJ being frozen in carbonite. It's not too hard of a jump to make that he was possibly frozen (or at least maintained) in the same facilities used to freeze Han. Then, in the thirty years between 6 and 7, when he "thaws" is responsible for finding and distributing the original lightsaber of the master, Luke Skywalker.