Question for animal lovers only!!!! What do you think of this?

We had some new neighbors move in next door a couple of months ago. All of a sudden we saw this yellow cat hanging around our house screaming and he looked starved. We thought the old neighbors left him or he ran from their new home down the street back to the old house. So we fed him for awhile and made a little covered house for him until we could get ahold of the old neighbors. Then we found out that the cat belonged to the new neighbors. They said it belonged to the daughter of the husband, but the wife said she didn't want it in the house! She doesn't care for cats yet she didn't want him to get hit in the road either. Then I told her we had seen 8 cats/kittens get hit in the road in the past 3 months. It didn't phase her. We live on an extremely busy street;

Okay now they claimed they fed the cat and put water out for it..;.it is no where in site!!! Secondly, they said they had a warm house for hit to go into…it is a cloth thing that water gets thru!!! It is not warm! Thirdly, this cat is DECLAWED!!!! The cat can't defend himself. We have been feeding him and lettting him in at night when it is freezing! He is in now bc of the snow – he is in the basement. We have other cats of our own. We can't stand to see him freeze and starve. He is finally at a decent weight bc of us! What do you think we should do? I was thinking of saving money and taking him to the vet (even though he is not our cat) and have him checked bc he has something all over his skin that is rough & like white flakes and scabs.

Anyway what do you think of this situation and what do you think I should do?

Again this is for animal lovers only – please don't say let him die or let him get run over or anything mean like that!