It's likely this was meant to be a "summer quilt" with no batting on purpose. If you seriously want to restore/save/finish this lovely quilt, I might suggest doing what I did on a ca. 1780 family quilt which is now at the textile museum in Williamsburg VA.
Using their perfect lighting, large tables workroom for a couple of days, I fully laid out the whole quilt and covered it with one large piece of thin, clear vinyl like you would use as a table cover. This allowed me to lean on the quilt without getting the oils of my hands on it as I closely studied the piecing and quilting designs. In my case, the vinyl allowed me to use a magic marker to copy the designs without damaging the quilt. Perhaps this would help you to figure out what the embroidery patterns are on your quilt.
What a lovely project you have ahead of you!
Jan in VA