Wow ! the shot of salvaged cars piled one atop another is heart wrenching due particularly to the fact these may well have been rust free examples by virtue of the Calif. tags on the 57 Chevy on the bottom level.
All you need to know about the times is the pump has "cents per gallon" permanently embossed on the pump. With a dollars worth of regular you got your water and oil checked (there was a reason that was needed), and windshield washed...Tire pressure on request.
That's quite a cantilever over all that glass. Speaking of glass, lateral movement would be a concern too. The engineering drawings would have been interesting to see.