This might be a Marx engine you haven't seen.....
Brought out from gathering dust back in the far dark corners, this Marx
#1829 was upgraded into a heavy road engine with Elesco, flying pumps, and
a coal-fired Vanderbilt quite a few years ago, with an additional pair of drivers and modified rods. To my amazement when I finished it, it runs very well. This was developed before the three rail manufacturers woke up to this wheel arrangement being one of the most popular on American railroads at one time, and produced any Mikados.
And it can do double duty, for the tender's rear truck revolves under the rear,
as it carries a Marx tilt fork coupler on one end and a Weaver #711 Lionel
compatible knuckle coupler on the other. The coupler not in use is out of sight. This engine can pull its weight in either Marx or Lionel compatible cars.