No, the problem is not the gift, the memory is the most important. You can make a memoir of the little experiences between you two, which is very meaningful and worth cherishing.
You can make a puzzle with his photos. He and his wife will play with it and look at it when they have nothing to do. It is interesting.
You can give him something he likes. For example, if he likes to listen to music, you can give him some MP3 or MP4 with good sound quality, and be sure to bring a good headset.
You can also give him a real doll made with his photos, which is very fun.
Don't forget to spend time with him, and it's best to call all the brothers to have fun together.