Blue Motorized coach (Mighty Mac like)

[Super]

If it is a factory error there would have to have been three painting errors, Blue instead of green, yellow instead of white and a painted roof which isn't on the green Mac coach. I have seen this version before but I think only in the Japan auction Lots. What makes this so much more interesting than just the colors is that it is a motorized coach meant to push a non-powered engine which is evident by bulky hooked coupling which should limit the choices of what it came with....Chuggington? Another point that may add to the detective work is that the engine is most likely not tendered since pushing both a tender car and an engine might prove to be problematic. So maybe we narrow it down to diesels or tank engines? Also might there have been a piece of equipment this pushed like a crane car or something?