The Automatic Merchandise Box Car No. 3454 was first produced in 1946 and Lionel would use this car to perfect the mechanism that would be used in the No. 3462 that premiered the following year. This mechanism was mounted on a sheet metal chassis that has four steps at each of the corners.

This SILVER box car has DARK BLUE lettering including a Pennsylvania Railroad logo above the car data on the right side. Today, a premium is paid for cars that still retain a shiny SILVER finish. Used Type 3 trucks that have electronic couplers.

The merchandise car came with six "Baby Ruth" plastic merchandise crates that were manually loaded through a hatch in the roof and were unloaded electronically with the use of a UCS or No. 6019 track section into a waiting bin at track side. The plastic crates are usually MEDIUM BROWN in color, but have also been found in RED and BLACK colors. These crates have been reproduced and the reproductions are BROWN in color and do not have the "Baby Ruth" imprint. There are three variations:

Variation A: used Type 3a trucks and the lettering is almost BLACK in color. The roof hinge pin was not visible on the end of the car.

Variation B: has RED lettering. This is most likely an early production run.

Variation C: is the same as Variation B, except that the lettering is DARK BLUE and the roof hinge pin shows through on the side of the car.