I'm just getting a chance to read this and really don't have much to offer as far as advice goes. There's not much that can be done if you don't know where they went. I would keep putting food outside at the same time everyday and see if he shows up to eat. If you do see him again I would suggest trapping and taking to the vet. Gosh from his pictures he looks pretty healthy.

Amelia is adorable. Are you going to trap and have her fixed?