Is there any chance that these pieces were from a finished quilt? It looks like there is batting sticking out around the edges.
Pieces like these should have been sewn onto larger squares which might be hard for you to do now if they have batting underneath already.
Two seconds more thinking: These would make great little bed top pillows. Cut them into circles, sew two together, stuff, and put in a center button. Give a couple back to the previous owners and keep the rest!
Jois