These green cars were Lionel’s first plastic passenger cars. The Madison cars were made of Bakalite which is a compressed granular material, not a plastic.
The Lionel 2400 Maplewood, 2401 Hillside, and 2402 Chatham were introduced in 1948. The passenger cars were cataloged in O gauge sets with the 671 turbine, and in 027 sets with the 2025 steamer.
It’s very hard to find clean undamaged boxes for the 2400 series Pullman cars because the trucks tend to twist and tear the boxes when the cars are inserted or removed. Boxes with all their flaps and no tears bring a premium.
In 1950, the cars were dropped from the catalog in favor the 2481 series yellow cars.