What might be an appropriate combination of coaches, 8-1-2 sleepers, and 12-1 sleepers for a NYC green set behind a new Lionel Hudson? Would all the cars be NYC? Scott’s website has some Pullman options. Which would be Pullman? The 8-1-2 pull-down menu has Pullman options but the 12-1 does not. What might the roofs be? Pre or post?
I'll let the true NYC experts weigh in, but I can offer some general thoughts. New York Central was quick to adopt lightweight cars for long distance trains starting in the late 1930's. While heavyweight cars continued to run, many were repainted into the two-tone gray scheme to match the new cars. I don't believe there were many if any Pullman green modernized New York Central cars outside of head end cars. Head end cars tended to keep the green paint later than other cars in the fleet also. On the NYC Modernized cars seem to have typically kept the monitor roof instead of getting a round or balloon style roof. Modernization is most clearly seen in the replacement of windows and the addition of air conditioning to the cars.
As for cars marked "PULLMAN", the Pullman Company until it was hit with an anti-trust lawsuit in 1944 owned the sleeping cars and provided the porters for the cars and leased the cars to the railroads. This would mean that "PULLMAN" would be in the large letterboard in the center of the car while the specific railroad name would be in small letters next to the vestibules. Once Pullman was forced to sell the sleeping cars to the railroad, the "PULLMAN" ended up in small letters next to the vestibule while the road name was in larger letters in the center of the car.
I have a two tone gray NYC Pullman with "PULLMAN" in the center and "NEW YORK CENTRAL" by the vestibules, but I don't have a photo of it like I thought. Many sleepers from this era also simply said "PULLMAN" on the side.
Head end cars, coaches, lounges, and diners were typically lettered for the NYC. The observation would be either a Pullman car or a NYC lettered car based on configuration. If it was a coach / lounge seating arrangement, it would have likely been lettered for the NYC. If it had sleeping car berths, then it would be likely lettered Pullman.
As for a typical consist, it pays to do a little research. Many east-west New Central trains in the heavyweight era ran as mixed consists. Again, the NYC experts should weigh in on this.
12-1s were a very common plan with 12 sections and 1 drawing room. The section berths were the more affordable accommodations. 8 section, 1 drawing room, 2 compartment sleepers which provided more private rooms. Both are common Pullman plans, so I don't think there is a correct ratio for a generic train outside of what you like.
I realize this isn't very concise or that clear, but in general I might recommend a baggage car, a RPO, a few coaches, and a diner all lettered for New York Central. I would then consider 12-1 and 8-1-2 sleepers and the observation car labeled for Pullman when that car eventually comes around as the GGD tooling is a 3 compartment plan with a lounge. That would be 8 cars which might be a bit long for a home layout but could fill in for any number typical trains and would look great behind a scale Hudson. If you wanted to go down to five cars, a baggage-coach, coach, diner, and two sleepers would make a nice train too. Many trains ran without observations so the rear markers would often be on the last sleeper as is the case with this green SP 12-1 in my collection.

Finally understanding that this run of cars is for sleepers and coaches only, I might consider 3 coaches (non-modernized), a 12-1 Pullman, and an 8-1-2, Pullman.
Any of the shorter Lionel, MTH, K-Line, Weaver, or Atlas baggage cars could be used for now for the head end, but colors are all over the place between those manufacturers if that matters to you.
The path to the other cars all depends on a strong run of these cars. Apologies for the length of this post! Final thought is that I really like these cars a lot. A few from my collection. I've been a bit indiscriminate when it comes to road names, but I really love scale length cars in O!
First is a PRR coach. I have coaches in PRR, ATSF, CB&Q, New Haven, Lackawanna, Erie & Canadian Pacific.

These are all 12-1s. My 8-1-2s are all PRR. I also have 12-1s in Erie and Lackawanna.






