I just got the new Busch catalog from my local German Hobby shop in Germany.
Inside they had a whole set of German mine buildings and stuff, in HO.
The New and Strange is, they have a German mine train that is HO scale, but runs on Z track!
They call it HOi/HOf. I have a few narrow gauge ho things and kind of know the scale. Roco and Eggerbahn was HOe and could run on n guage track. There were a few things from small companies in HOf (if the German Army WW1 Brigadelok was in HO, it would run on HOf or Z scale track.
Anyway, looking in the catalog, it shows a lightweight small engine, and the cutaway looks like a faulhaber type motor. It runs on 3 V and uses 2 AA bateries.
They say to use Maerklin track, but to give it traction, there is metal plates that are added to the track, and a magnet is used on the engine. (Eggerbahn had somthing simular with steel track and please correct me if I am mistaken this is used with t scale too?/)
So maybe some of our German Friends knows more about this engine. It looks like there could be possibilities for scratchbuilding. The mine cars are interesting as the Z scale wheels are ope on the outside and flat (no pointy ends that go in the trucks) again uses for kitbashing???