I dont think Dre has much that is complete and ready to go in his vaults. Lots of sketches and discarded concepts, yes.
Full songs or even full beats? No. A lot of what he classed as subpar for himself was passed on to other artists later so I think we've heard a lot of what he's made.
Quik on the other hand I think has a vault packed to the gills with hot ish that he wont release for whatever reason.