Lionel intorduced the 2461 transformer flatcar in 1947. The gray base is diecast metal, and the transformer is plastic. The first cars were made with red transformers. Later production runs had black transformers. Red is harder to find and more desirable.
The insulators on top of the transformer are usually broken. On the car above the two on the right are broken off.
Replacement insulators are available and are easy to install. Original insulators are translucent white plastic. Reproduction insulators are dense white plastic and are flat colored.