Have you actually seen inspected and held the snake? I have seen some animals in pretty bad shape off of craigslist. They usually end up in a reptile shelter near me that i have since stopped going to due to the numerous snakes with issues that I did not want to bring home to my collection since it grew. Be careful. Hope it all works out. As for heating, what did the original owner use and did it work? If so i would just duplicate what he\she did.