I have wanted the Johnstown #357 in two-rail (for the scale-flanged* wheels) to operate with the rest of my trolleys/interurbans off the overhead. And because I had the opportunity to run it at a Branford Members' Day:
(my photo taken at the 2007 Members' Day at the Branford museum)
Maybe one day I will find one.
*autocorrect suggested "scale-fanged"