When I was in High school I lived in my own apartment, and had to work at filling stations to pay rent and eat.
It was just as you say, we checked everything, cleaned the windshield, we would air your tires and top off the battery and radiator for free, and you got drinking glasses and stamps with minimum gallons bought, we were courteous, and kept a rag in our pocket to wipe you headlights, or the dipstick, and we knew how to give you directions.
It was pleasant work, and people were nice and would engage you and be appreciative, we were a more homogeneous, connected community of fellow Americans back then.
$0.28 in the late sixties in Mass. I could fill up the first 5 cars I owned for $5 or less.