I received the new Searails PowerMAX! in the mail a few days ago from Republic Locomotive Works. I've had a Marklin old time passenger car waiting for modification for a while so I thought this would be a good use. I shortened the Marklin car, added the back porch to hold a MTL coupler, some side and front skirting, a headlight and a pilot from a Marklin steamer that I had removed some time earlier. This new unit runs smoothly and quietly and negotiates my small humidor layout easily.
Thats a neat little critter that you made. I hope to see some some more little critters that used this mechanism. Stoney Smith makes a dummy Z scale GE25T. I wonder if it could be modified to use this mechanism.