Great save. Your problem-solving skills are in good working order! I had a somewhat similar situation last year when I made a quilt for my MIL from my DIL"s shirts. He had passed away a couple of years ago and I asked her if I could have his shirts for quilting fabric. Since she was going to give them away anyway, she gave them to me. She didn't know I planned to make a quilt for HER from them, though. Found the perfect pattern in a Bonnie Hunter book and made the quilt. It has two borders, one of which is pieced from the shirt. Some of the shirts I had were solid, but some were striped. Well I used solids on two corners and stripes on the diagonal ones. One of the striped corners just happened to line up beautifully when I mitered it. But, oh my, not the other one. I hadn't even considered the stripes when I was assembling the border pieces.
Of course, I didn't have a long enough piece left over to fit the corner. However, by taking a longer piece from the side of the border and fitting some others in place, I was able to get a long piece and managed to get those stripes to match. Boy, was I happy!
You'll probably always "see' your patched corner, but no one else will. It's your (and now our) little secret
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