The Lionel Track Cleaner No. 3927-75 was released at the same time as the No. 3927 in 1955 and was available until 1966. It was later produced again in a blister pack in 1968 and 1969.
The track cleaning fluid was non-flammable and it replaced the No. 927-3 which was flammable. The reason for this was that it was used with the No. 3927 Track Cleaning Unit. With the electrical current powering the sponge, and the resulting sparks from the pick-up roller on this unit, there was a very real threat of fire.
Because so many of the cans that contained this fluid are found rusted, it is believed that the cleaning fluid was water based. Many times the contents are found to have evaporated from the can even when new and unopened. It has been found in this condition even from those cans that have been unopened in blister packs.
Early versions with have the printing on the can lithographed, but later issues used a paper wrap-around label. This accounts for the two variations:
Variation A: DARK BLUE lithographed can. The most commonly found variation.
Variation B: LIGHTER BLUE printed paper label.