I bought a 71 Mach 1 in summer of 73. It was sharp, but with a dog of a v8: the 351 Windsor. By that time it had also seen 3 winters of road salt. The original owner commuted almost 80 miles round trip per work day year round. By the spring of 76 paint was bubbling bad in many places, especially below the tail lights. 5 1/2 years old, and becoming structurally unsound.
I had the 351 Cleveland
Rubber in all 4 gears
Only guy who could match me had 383 ‘71 Super Bee