Since you plan to use it, I would wash it before starting to repair, unless there are holes in it, which should be cover-basted with netting. I had a 20s quilt that looked okay, but after soaking in the bathtub, the water turned Hersey chocolate brown, ugh it was awful. Add a two or three drops of liquid soap and let it soak in cool water in the tub for around 30 minutes, gently hand agitate it and push to the side of the tub to let the dirty water drain out. Rinse two or three times, as soil requires. Squeeze it to the side of the tub and gently press the water out. When lifting use care to grab large amounts of quilt so as not to break stitches. Have someone help you carry it out of the house on a sheet, open the sheet on the grass and CAREFULLY open the quilt to dry. Cover with another sheet to protect from birds and animals. This is how I wash all my good quilts--I want them to last.
Oh, the quilt fabric looks older than the 20s. You date a quilt by the newest fabric, not the oldest. We all keep our fabric for years before it is used up and so did earlier quilters. There a number of fabric dating books available.
Happy repair
SandyQuilter