Old quilts, sewing question?

So I found some old quilts in my basement. The note on them from my deceased grandmother says that they were made by my great-great-great grandma back in the 1800s. They are beautifully made with a lot of detail, but none of them were ever finished, and none of them have backings. I really want to finish them so that I can use them and display them in my home. However, I'm a bit unsure on some things; would it hurt them to use a sewing machine on them? The fabric is over a century old and I don't want to ruin it. They were all originally hand-sewn. Also, would it be safe to wash them in the washing machine? Or hand wash them? Help please!