Lionel 671-235 Center Wheel - The 671-235 center wheel first appeared in 1947 as a replacement for the nickel tire center wheel that had been used previously. Lionel issued these center wheels without the insert for the side rod screws and sold the inserts separately. As is the case with most things Lionel, it was rumored that these wheel were tapped for a side rod screw, which they were not. Later Lionel issued the 671-240 center wheel, which is the 671-235 center wheel, but with the insert already installed. The wheels we have are new old stock postwar.