Carl,
I am sorry that I do not know the Lionel part number for the Dome Floor. There is no parts diagram in the car box. The seats are separately applied to the Dome Floor, and they are inserted into rectangular holes in the floor at the factory.
My "Challenger" Camera passenger car had three seats installed tilted, and they needed to be moved to stand properly. One seat post broke, and I had to glue it and the two people in the seat to the Dome floor to secure it.
The Challenger Camera Vista Vision passenger car is 2027270.
Sincerely, John Rowlen