Earlier this summer I made a set of "stubby" or "Short Line" freight from some old 10 series Lionel freights (here). I still had the bug so I made another set, using the smaller 100 series cars.
The 10 series shorties pull well behind a little red "Little Chief" McCoy loco.
But the 100 series are a lower truck, so the Little Chief won't work; I needed an engine with a correspondingly low coupler.
I had an MTH Lionel 10 that had come with an RTR set; the cars had since been sold off, I had experimented some with the engine, and it was the perfect candidate. I chopped 1-3/4" off each end of the frame and the shell hoods. No room for the PS board, so out the window - it's all conventional now. The shell is 6-1/2 inches long now, and the motor entirely fills it... it's a tight fit. Call it my No. 100, and Baby Blue seemed appropriate! Have to be careful though - it has all the traction and power of an MTH can-motor locomotive, it flies!
The 116 ballast car just does not convert to a one-truck shorty: it's saddled between the two trucks and dumps out the middle between them: chop this and put one truck under it in the middle, and you've got nothing. So I used a 100 series frame but put a side-dump bin from an 809 on it.
Another fun little set to careen around the layout! (click to enlarge)