I am so sorry for your loss, and your gift will bring comfort in a special and unique way. The idea of using some of his clothing to sash the photo blocks and/or to make simple 4 or 9patch blocks to scatter among the photo blocks will add to that comfort. If I were making it I would back it in a really good, soft flannel that represents something about him water, outdoor scenes, sports, his favorite color etc. something about flannel always feels like a hug to me. Prayers and comfort for you and your family.