I had an engineering colleague (Scottish* BTW) who pulled that game at group lunches this time of year . He would also NOT participate in leaving a tip .
During the days you speak of , ‘Mom’ was a housewife – there to make breakfast before school ( that place we all walked to – and from ) and lunch at mid-day , not to mention the family evening meal . Meat and potato meals – with only one wage earner , not two . I lived within broadcast range (via rooftop antenna) of Detroit . I remember dealerships there advertising brand new full sized Fords , Chevy’s and Plymouths for $1500 …and no sales tax , either . Ramblers less than that , and the Nash/Austin Metropolitan around $ 1000 ?
*My family on both sides is 100% Highland Scottish , on this side of the Atlantic for over two centuries .