That's neat that they restored it and kept it running so many years later, Kingcreek!
My first car was a bright yellow (ticket magnet) 1971 Mustang Mach 1 with the 351 Cleveland. I got it my Junior year in High School with as I recall, 60ish thousand miles on it. I kept it until I was 22, at which point I was working in the oil patch and wanted a truck. I sold it to a buddy who had always wanted it, but he only kept it two years.
I remember seeing it driving around town restored nearly ten years later. I recognized the license plate, and they kept it the same color with the same black trim scheme. I recall looking up the value and being absolutely shocked. It was something like $30K. I had paid $1700 for it. I can only imagine what it would go for now in a restored condition. I kinda hope it's still out there somewhere cruising some Main Street on Friday night like I used to do with it.

Edit: Ha! Just for kicks I took a look. Except for the engine, this is identical to what I had, down to the GT500 hood scoops and the rear spoiler. And going for $30K all these years later. The other one listed there is going for $110K.
https://classiccars.com/listings/view/1768358/1971-ford-mustang-mach-1-for-sale-in-palm-desert-california-92211