Yes, Hammer did record an album for Death Row Records. I've heard a good portion of it and I will tell you right now, the music is hot. Hammer never actually signed a deal with the label which is why they wern't able to release the album, technically. There were a lot of things going down behind the scenes that stopped that project too though and that had more to do with it than anything.
Sam Sneed, Danny Boy, J-Flexx among other artists all have unreleased albums that were recorded during their stay with that label.