Sylvester needs help

This is a cat that showed up in the neighborhood. We started to feed him all the neighbors did and he kept coming back. We called him Sylvester. He would come and go he was a feral cat and wouldn't come near us. My husband build a home for him. We loved this little guy and wanted him to be ok.
We tried to get him in the house but he would never come close enough. He went missing a few months ago. Came back with a half of a ear. We gave him some antibiotics and turmeric for inflammation. It got better.  He took off again and we though someone took him. When he showed up I couldn't believe what I saw. His ear was gone and there is a problem with his jaw.

I was able to get a trap to trap him. Now he is at the vet. 
I don't have a lot but I do have a lot of love for animals. So I'm looking for some help. I would love for him to be rehabilitated. To do that it will cost a lot of money... For starters this is what I can see until the vet tells me more... his missing a ear, can close his jaw, neutered and foster care.

I don't know what the cost will be.  Any help... big or small would be appreciated.

I will send up dated pictures.