^^^ What the heck - I had a few '69-'70 Mustang Sportsroofs back in the day, NEVER a difference in the way the pleats ran.
Gotta be thousands of them out there, so it's really bold - I mean, foolish - to try to BS that.

I do recall a few decades ago seeing that mottled look on burnt orange seat bolsters on a '70 GTX, but I don't know if that was legit/recovered/whatever.