That's a good guess (a healed wound from live feeding) but more likely a minor rub against something abrasive. (That's a very odd place for a bite.)
Your other snake: you'll be seeing that pink spot for a very long time, learn to ignore it. Scales don't regrow, but it might darken a little eventually.
(I guess you could get him a hair-piece?-but I'd just tell people he's a "bald python"...) Seriously, he's very handsome, don't worry about it.