there is no such thing as registration in Pa. the problem is you made an illegal transfer of a hand gun already. there is no great way to fix that. The only way to remedy that is to go to a gun shop and do a transfer. the problem is who do you transfer it from? the reality of this situation is you have a gun that "belongs" to the last owner on paper, not you. so if you commit a crime with that gun and wipe the prints off then drop it at the scene; the police will eventually end up at the last "paper" owner's door. He is the one that has really opened himself up to possible problems.