At some point during the modern-era, Lionel switched from a design which was essentially identical to the postwar version, to a complete re-engineered can motored version. If you look at the parts list, the newer trolleys are of very different quality. The chassis, motor and pickup are essentially the same as the modern era handcar. The sliding shoe you reference looks like the exact same part used on modern handcars. Up until the early 1990's the handcars used a copper sliding pickup with a rounded edge that wouldn't pick switches and crossings. Then they switched to a chrome version with a square leading edge that snags everything. See the difference in the photos below.