i think you already did the best thing you could by having the visit where he was used to living.
i second what withay said too....and will add, i would make a book of your family. sometimes i can find at the bookstore a boardbook version of a photo album for kids-they are nice and sturdy so they are toddler friendly
...but you can also just go online to like snapfish or shutterfly and make a paperback one fairly cheap. put pics of you together with him, big pics of your faces, your house, any pets, his room, etc. add one line narration for anyone reading it to him..simple like, "this is sam the cat." also...i would get a stuffed animal of some sort....sleep with him for a night...or as many nights until you see him next...and then bring him as a gift. i know that sounds weird...but it will still be new...but it will also smell like you. smell is a big deal to little kids. i think these are 2 great things that will help him to recognize you and feel more comfortable.