Warning warning Will Robinson.
Just had a siminar last week at quilt guild.
"to date a quilt, the time line is as early as the latest age of fabric used" So:
her example,
1980's fabric was used on a great grandmother's quilt. The quilt then turned into a 1980's quilt. !! How awful !! So, please, it is up to what you want. A quilt that has warn, even because of the type of process the colors the material deterioted, or change the whole age /worth of the quilt.
Please, consult a person that knows before working on the quilt.
Good luck!
Ell