Thanks for your helpful comments, David. You might be interested to know we are travelling 50 miles on Friday to meet a cat called Jojo with the possibility of giving him a home. Will keep you informed!!!
Sad news, I'm afraid. although Jojo was gorgeous (I will post a photo at some point)and very affectionate, we hadn't been told the whole story about him...like he was feral for 5 years and then had 4 years in a barn until he started attacking the other cats. He had a go at poor old Sprocket and would have gone for Sox had we not intervened. So, we decided he needs somewhere in the country and has gone to a lovely small holding where he also has a large porch to himself.
He was only with us for 2 1/2 weeks but we cried our eyes out when we handed him over!!!
Oh dear, that is a sad tale, Oriole. Feral cats that survive that long do not easily re-adapt to domestic living. Every other cat becomes a threat. It sounds as if you did the only correct thing; if he has space and the wild he will do OK.