You had no reason to think the person wasn't taking perfect care of them. Not your fault.

I second the suggestion above about testing for parasites. Get them into proper housing so you're certain they have appropriate heat and humidity and hiding spots, then remember not to try to stuff them with food right away. Give them time to settle in and get their digestive tracts back to normal before feeding.

As far as a wound, once the vet takes care of the wound, you'll be surprised how quickly they heal up and after several sheds, there probably will barely be any sign.

Good luck!