I never had good luck with abandoned cats. Maybe there is a reason someone abandoned it .
I do wish you good luck because when you take in an animal it's hard to let it go.
I took in a male cat that was hanging around, had him fixed, but his nature changed.
After a year he began to mark the house. Even though he was fixed.
I've learned recently that I could have possibly kept him.
I've had communication with my vet lately and it might have only been a feral cat
outside coming around that caused that behavior.
So I would urge you if there any behaviour like this, contact your "dog catcher" and
ask for a human trap for a possible feral cat coming around.
The feral cat will bring out the worst in your new found friend.
good luck Bill, but if not, explore all possible solutions.