The Lionel Lines Berkshire Type 2-8-4-Locomotive No. 726 was first issued was in 1946 and it was last available in 1949. Reissued as the No. 726RR in 1952, this locomotive did not have Magnetraction. In 1950 Lionel would introduce the No. 736 as the next generation of this locomotive that was equipped with this feature. With magnetic material being in short supply during the Korean War, Lionel would revive this locomotive and issue it as the No. 726RR in 1952. The number "726" is rubber-stamped on the sides of this issue.

There would be many production changes that occurred during the short period that this engine was manufactured. We’ve noted the major differences below:

Variation A: Produced in 1946, this version has the fire box plate on the bottom that would extend beyond the ash pan and reach above the rear drivers. These drivers would be "Baldwin Discs" that have the "Baldwin" name cast into them. A close up of these driving wheels is shown to the right. This variation has nickel plated flag holders on the pilot, with no simulated front coupler.

Variation B: Produced in 1947, this version has a revised boiler casting with lengthened sand domes, and the directional unit’s lever protrudes though a slot in the top of the boiler. It has blackened flag holders and the bottom plate reads, "Made in U.S.A. / The Lionel Corporation / New York, New York."

Variation C: Produced during 1948 and 1949 this type does have the simulated coupler on the front pilot and the whistle in the tender is made out of plastic instead of the previous production’s metal housings.

All of the Berkshires that Lionel produced were designed to run on the standard O Gauge tubular track of the post war years and will not operate properly on the tighter curves of O27 Gauge track.