Id side with the op here, obviously hes taken the animal in, treated it well, whereas the alleged original owner doesnt seem to have treated it very well, in the interest of the cat, it would be better off with the op, my neighbours cat is a frequent visitor to my house, she actually waits on my wall every friday night for me coming back from the pub, because she knows ill pet her and give her a bite to eat, im mainly a dog person but she's the friendliest cat ive ever seen, shes the only cat ive ever seen that will run out to greet you, much in the same way as a dog would do.