They need to look at that quilt really closely. My great aunt made a quilt with large squares like that. One of the squares was a very cleverly sewn pocket with a small opening that had a label inside. The label may also be sewn into the border with a lighter color thread or even into one of the corner squares. They may need to use a flashlight with an led to see the label. They also need to check for the same things on the back of the quilt. The label may be tucked in like a flap.