Atlas N - 3744/3753/3754/3755 - Model train freight carriage (4) - Piggyback flatcars, 50 ft, can carry 2 trailers, 20 ft vans - Southern Pacific, Conrail, Canadian National, Canadian Pacific

4 wagons of the Piggyback flatcar type, 50-foot, with 2 trailers of 20 feet each, from the Atlas brand — from different companies.

3744 - Southern Pacific, own trailers
3753 - Conrail, trailers from American President Lines
3754 - Canadian National, trailers of their own
3755 - Canadian Pacific, own trailers

Release date: 1988

The wagons come from a long-stored collection and are almost certainly unused.
Photos are part of the description.