Here's my last installment of my research of the "post-war", Chicago-Twin Cities corridor parlor cars:
Did some back checking on the CB&Q Twin Cities Zephyr: The Dome/Observation car appears to have had 29 revenue "parlor" seats, 9 forward of the dome and 20 rearward of the dome, all of which were non-anchored chairs - it seems unlikely that these seats were numbered and assigned, so one can only guess at the scramble for the rearward most seats at boarding time in Chicago and St. Paul. Two anchored seats in the round end of the car appear to be non-revenue lounge seats, along with the 24 seats in the dome. Plus there was a Drawing room (under the dome) that could hold four or five folks, and the restrooms were also under the dome.
The TC Zephyr's Parlor Car had 28, anchored, rotating seats, 14 single seats on each side of the aisle, served by 7 large windows on each side of the car. There was also a Drawing room. Restrooms (men's/women's) were at opposite ends of the car.
The Chicago & North Western parlor cars had 22 anchored, rotating seats, 11 single seats on each side of th aisle, but ironically, these 11 rows of seats were served by only 10 windows. The car also had a drawing room (with its own toilet) and mens and womens restrooms. The car also had a smoking room that could accommodate about six people that was probably none revenue.
The C&NW Twin Cities 400 observation car, had 12 anchored, rotating parlor seats, in six rows, but once again, only served by five windows on each side of that part of the car. The lounge area in the rear half of the car had seating for 29, plus a service bar. Restrooms were at the forward end.
It's hard to believe, with all this space and comfort, that post war train ridership declined as it did. Even first class in the Acela doesn't match these parlor accommodations.