Usual Thirties passenger trains,how were they consisted?

[Texas Zepher]

St Francis Consolidated RR

It does rather bring up the question, though, of what a railroad that apparently couldn't afford streamliners and smoothsides be doing pulling six or seven nice old heavyweights with two Alcos. If they had that many customers they would have the money to buy nicer stuff, wouldn't they?

No not necessarily.  Even big railroads couldn't just run out an buy all the streamlined equipment they wanted.   The Santa Fe ran its heavyweight cars well into the 1960s.  I've seen the Santa Fe PAs on the point of many a heavy weight trains.  I think the California Limited was one of them.   It was only when the big ticket trains started loosing passengers that the surplus streamlined equipment got handed down to the second and third class trains.   The Wichita-Pratt daily used a 1926 vintage combined car (running behind a GP7) clear through to its end in 1967.