Agree with some of the others BUT since your location has
many quilters ---
I would find an apparaiser even by asking a LQS for info for a name and number to contact.
That person would probably give you most info even on how to wash/clean and repair it because they see it in person or maybe ask for certain info via a photo .
Appraisers cost me $20- $30 but for something so special I believe it is worth asking someone who is trained.
Although many on this forum are experts too.
Also you would get the answer re the age of fabric. Explain that you need info as most app would be happy to help save a family piece rather than charge you a fortune.
I find them at quilt shows or thru a guild.
I like the idea of a light color sheet/backing fabric put on as a mehod of restoration.
It's a real treasure