Can you put some posters up in your area saying found cat? Not that fact that it has a lion cut nor the fact that it is declawed on all fours
or you could have any loser showing up. Just the colour and sex. It's possible he just managed to escape.
Bless you for taking him in - at least for a while. Hopefully someone will show up soon. I would ask for proof though that it is their cat. IE: lion cut/declawed.
I wish I was closer. I would babysit him until owner was found. He actually doesn't look too thin in the pics. Looks about right.
Good luck.