You can garantee it came with mirrors, was required on most everything I can think of by '70.
The difference of location varies by state. Typicaly the drivers side is always required and the passenger mirror is only required if you dont have a clear view out of the rear window for the center mirror.

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P