If the blocks are really old I think I would just take them to a reliable framer and have them placed in a shadow box frame under glass like an old document, maybe add a card with all the information you can gather about them and hang them in my sewing area out of direct sun light. Or contact a quilt museum for more information, on cleaning, sewing with them, and the best way to showcase you treasure. I'm sure they will be more than willing to help you.