Is it possible to some how clip a note on him? That way if he does have owners, they will know that he has been visiting you and that you are concerned about him. He obviously doesn't have a collar on, but could you maybe get one or somehow otherwise get a note on him? Of course, if they don't returnt he note or call you, you will never know if they got the note or if it just fell off in Merlin's wanderings.

Otherwise, you could try talking to the new owners of your house, explain the situation to them and tell them you'll come back for him once your house is built. You might even offer to pay for the food they leave out for him to make it that much easier. Hopefully they won't have a big cat-aggressive dog that will scare him away.

Tough situation but I know you'll figure something out.

By the way, not to change the subject or anything....but....we haven't seen those adorable babies of yours lately. I'm sure they're looking all grown up by now.