I love the idea of using something old to make a memory gift. Maybe you could make Christmas ornaments for family members. I did this for a friend - ornaments from a favorite sport coat that her father wore. He was a pediatrician and I made "stuffed" rocking horses from the fabric and glued them on a tongue depressor that I had soaked in water and bent to fit. Everyone thought they were great and each family member had something small to keep. I think your shirts would make wonderful "stuffed" ornaments.