When I am rehoming cats and dogs, a vet reference is absolutely required of any adopter who has owned an animal in the last five years. It may not be directly indicative of the care these snakes would receive, but it could certainly shed some light on the sort of care the adopter gives their other animals. If I call on a reference and the person answering the phone immediately (without having to look up any information) says "Oh! Mrs Smith! She comes in all the time with Fluffy and Bubba and takes great care of them", that's going to be a lot more positive than if they say "Hmm...let me find the file. Ah yes, we haven't seen their pets in a couple of years, and they only come in for the rabies shot".

Same thing at the vet I work for; I'm always happy if I can give a positive reference for a client when a rescue group calls. Vet references are a standard part of any responsible rescue screening.

Sorry to hijack the thread, and glad to hear that the snakies sound like they've found a good match. :-)