One of my grandsons was an exchange student when he was 14. I made him a quilt for his dorm bed at his new boarding school. The first thing he said when he got back was that he wanted to make a quilt with me, just to get back into his "real" life. He stayed with me for a week and we made a lap robe for his "other" grandfather who had suffered a stroke. It was wonderful working with him. I'm telling you this because you might really find it fun (and even enlightening) to make the quilt with your brother. You would set the limits and he obviously is capable of making the design. You could show him how the pieces go together (and you could do it together, perhaps). It could be a wonderful adventure and a wonderful memory you will share for the rest of your lives.