So an all-Parlor car train would be the corridor version of an all-Pullman sleeper car?
Yes, both sleepers and parlor cars were considered first class. Any train which had a first class lounge and parlor cars, the parlor passengers as well as the sleeper passengers were allowed in the lounge.
I do not think there were many all parlor car trains besides the Merchants Limited, but if they were they were considered all first class.
There was a time when Long Island RR had parlor cars going out to Montauk. Some parlor cars had private rooms,like drawing rooms, probably not used for beds but for private friends or family space, good for private parties with 3 or people.
To re iterate:
coaches
sleepers (or "pullmans")
slumbercoaches
parlor cars
were ALL ticketed revenue space.
As oppposed to domes, lounges, diners, observation cars, etc.
Some parlor cars, many in fact, were combined with other kind of space in the car, such as parlor lounge. The parlor part would be reserved space, the lounge would be a place to wander to if you desired, just like today.
Again, "Pacific Parlor Car" is all about a catchy sounding alliteration, very clever, very neat. But it does kind of confuse the situation by leading people to think that a parlor car is a specialized lounge car. It is not. A parlor car is where you space is. A lounge, includng PPC, is a place to volutarily visit.
Ad mentioned in my earlier post, parlor cars decreased somewhat as coaches improved.
Some people who are more purist than I do not like comparing business class or Acela first class with parlor cars. but I think it is close enough to make sense. Exact seating etc can vary. I have seen parlor cars which were a long row of single seats on both sides
One thing I try to point out from time to time is that there were many railroads, they were not responsible to each other, they could call anything anything. There was not a consistent national corporation like Amtrak. To study the old lines be prepared for considerable variety.
For a few years there was a parlor dome on what was then called the Southern Crescent. This car was originally on the Wabash Railroad from Chicago to St. Louis. It ran on the Southern Crescent from Atlanta to New Orleans. The downstairs was reserved parlor space, the dome above was for all passengers.I think some people on it were confused and they thought the downstairs was a lounge.