Here he is, all neutered, he passed all the medical checks and he is at least semi-feral.
Or just a very aggressive grumpy man!
I kept him over night in a dog crate I borrowed from a friend and fed him so I know he was warm and not hungry when he left this morning.
I will keep a look out and feed him if he comes back.
At least he will not be able to father any more unwanted litters!