Well, I'm still confused. The Sydney & Louisburg Railway wasn't built until 1895. The passenger cars they used were built in the 1880's. If you're asking about the one at the Louisburg Museum, that a 60 foot coach built in 1881 by Rhodes & Curry. It was never owned by nor had any affiliation with Pullman.
I think this is the bottom line.
1. You are confusing the word "Pullman" to mean all passenger cars. The vast majority of passenger cars operated by the railroads were not Pullmans.
2. The CN may very well have run 50 foot open platform cars at one time. They weren't Pullmans but they were passenger cars.
3. The 50' Roundhouse open platform cars are close enough if you just want cars that look beautiful. Buy a set lettered for Canadian National and be happy.
4. Some steamlined cars, both Pullman and non-Pullmans, were delivered in stainless steel with fluted sides. The majority were flat sided and painted in the railroad's color scheme. The railroads didn't generally repaint stainless steel cars because they didn't rust. The chrome I wrote about on the CN cars was specifically on the passenger handrails only.
I think our language barrier is making it difficult for both of us to follow what the other is saying. I wish I could speak French but I'm lucky to get by with passable Spanish.
Do you have a friend who reads English well but also speaks French? If so, print out this thread and ask him or her to translate it into French for you. I think you might have a better idea of what I have been writing.