What a pain, what a bummer...
This is the first quilt I'm selling too, so there was no way I was going to give it over with mistakes in it. So I took to the internet, and looked up ways to patch quilts. Georgia Leigh has a good tutorial, but I modified it a little bit for my quilt.
To start off, I measured the two squares in question and made a paper template of the exact size.
Next, you'll want to cut a square of fabric at least a quarter inch larger than your template on all four sides. I didn't have any extra fabric scraps from the quilt, but I did have a lot of small squares left over. It made for small seam allowances, but it worked.
Press the sides around the template with your handy dandy iron, then remove the paper template.
Perfect little square! I pressed it a lot with the iron because of the very small seam allowances. And to be extra safe, I cut a piece of fusible and ironed it on to keep everything together.
Huzzah! Tiny patches!
I laid the patches out on the quilt where they were going to go- I was going to sew them straight on top of the messed up squares. But I didn't like how it looked- you could definitely tell that it was patched, it was layered and 3D and terrible. So I ended up completely removing the frayed squares and hand sewing the patches on.
Looks like it was meant to be there!
Overall, I think it was a very successful endeavor into repairing a quilt. If you have any suggestions to improve the process, leave me a comment! Thanks!