The Track Bumper No. 260 was produced beginning in 1951, and would continue to be available until the end of the post-war period in 1969. During this long production run there were several changes that occurred. The first was caused by the introduction of "Super-O" track in 1957. The feet of the A Variation of this bumper would not fit between the ties of this new track. As a result, Lionel would redesign this bumper in 1958 so that it would work with this track (B Variation). During the last two years of the post-war era Lionel would make this bumper out of BLACK plastic and would sell them in a Hagerstown ORANGE and WHITE box. This C Variation is considerably harder to find.