If you are done with them maybe donate them to a good cause or if you want $ sell them on the baord. Can you put some blocks together, like four 6 1/2 in. blocks next to a 12 1/2 inch block? I don't know if I would want all that filler from the sashing. How about putting same size blocks all together to make one project or lap quilt? Or if you want a larger quilt put all same size blocks as a center and tehn put the other same size blocks around it, like all 12 1/2 in. blocks to make a center and all the 6 1/2 in. blocks around it like a border.