I've never posted video, so can't help Andre. Sounds like the 999 is running and manufacturing ozone just the way it was designed!
To keep the photos going, here are a couple ideas for cabooses to run with Marx 3/16 scale trains.
I bought at auction a pair of prewar AF 3/16 scale, O-gauge cabooses. One was in better shape than the other, but was missing one coupler, so I tucked the humungous AF link coupler under, then added a Marx tab-and-slot so it could run with Marx 3/16 scale cars. The other was converted to ATSF. I moved the cupola, painted and decaled it, made a toolbox, and mounted Marx trucks. Sounds simple, but the roofwalk was not continued under where the cupola had been, so I cut a length of brass stock and JB Welded in on, smoothing things out with putty.
The very common AF 3/16 postwar caboose has Marx trucks under it. It's quite a bit smaller than Marx cabooses - those trucks look kinda large under it.
