Originally Posted by tessagin

Not knowing how old these block are, I would do a tug test. Saw a post on Bonnie Hunter and she was getting ready to work on some vintage fabric. She had sewn a few together and they tore right in her hands. She took a couple other pieces and tugged. The fabric had broken down and became unstable. She stopped using them all and just put them back. This was this week. May want to do a tug test just in case. The fabric was almost 100 years old she stated. Worth a shot. Yours may not be that old but I would do it anyway. Hope it passes the tug test.