I think I would replace the holey squares and then take it to a long arm quilter. With a sturdy back and cotton batting, I think it would be a very nice quilt!
I don't like tied quilts. The ties can rip through the backs due to people sitting on the quilts. I don't know how old your grandson is, but my son has brought several quilts I tied years ago to me for repair. And that is a pain!