Thank you all for your kind messages - I am learning that I do have some caring neighbours as I have had many phone calls - mainly from people saying how well they know my cats. I have learnt a lot about the lives of my cats.
They are very well loved around here and visit many kitchens and gardens and put on all their shows for people. I have been to every house in my area and dropped leaflets and had sheds and garages opened. A gardener did say that he has found my cats in his van before and in my heart of hearts I feel that is what happened to Alfie. So trusting, I am sure he jumped in a van and has been driven away. He really is not a brave cat so goodness knows where he is and what he is coping with. I want to think he will make his way home and I am walking a wide radius calling him, I just wish someone would take him to a vet to be scanned as that would bring him home.
Alfie doesn't have a collar on, but his identical brother Oscar does. Poor Oscar is permanently being brought home by caring neighbours believing they have found Alfie - he is becoming quite disgruntled by his normal life being so disrupted. I do keep stressing that if Alfie was near he would come home, he wouldn't simply be sat in the gardens, but people are simply trying to help which is a comforting thought.