Here is the vintage Paya unit.
Bub made a nice clockwork trolleys in single and two-car several versions.
also seen dark blue and maroon versions of the one on the right.
Keim also had a neat battery powered 2-car unit
also found in a 3-car version in two-tone green. Again battery powered
Unfortunately the Keim clockwork trolley has rubber tires and ran on a single rail.