I think it may be best to take them to the vet and have them put down. The one without the prolapse may be a nice pet in time, but it sounds like they've been in substandard conditions for far too long. What does he want for them? It comes down to weighing that and the potential vet costs, deciding if it's worth it for you personally to put in the effort.

We see terrible rescue situations like this far too often in the hobby.