Not sure if this will help but I had a very similar problem. If you take a close look at the lock mechanism, you will notice a small caul with notches to lock it in place when the door has been closed. Its kind of like a ratchet action. Mine was worn so bad that all that was left was lines where the notches should be.
I took a punch and removed the caul, put it in the vice, re-filled the teeth put it back in, and what a difference. My door shuts really well, no more rattling!! I could be wrong but I think most of us could avoid buying after market locks if we would rebuild them. I don't think alignment is always the problem. Hope this helps
