Take a good, well-lit photo and put it onto the flyer. Even the most average kitties get chosen if the photo is nice.
I agree with Jade. Flyers are a good idea. I wish you the best of luck. I found a stray, loving kitty some time ago and nobody wanted him. I couldn't take him although I would have loved to. Out of desperation, because they were going to kill him at my apartment complex, I took him to the county shelter. So unwise......kitty got ill with URI and was euthanized two weeks after being there. He had even been placed out for adoption as he was a total love.
Talk to your vet, and see if they can help you. We don't even know where you live and probably don't live near you. I would take him in!!! I would!! I hate knowing about kitties in need of good homes and not able to find one.
Good Luck!
You might try making up some flyers and asking your local liquor store if they mind if you put one in the window as well as put them up around your neighborhood. Or at a laundrymat. I say this only because my folks own a laundrymat and have a board up for people to advertise. My vet also allows flyers for "lost pets" so maybe your vet will allow such an advertisement?
Best of luck to you and the little one. Sweet of you to try and help him.