Hello,
I am aware of three sources of Marklin pictures and information:
Search more than 1.7 million objects and 22,000 linear feet of archival documents.
(the last one, collection number MC.322911 looks similar to yours, albeit less fancy. I am keying off of the one large rectangular vent near the top of the firebox)
Toy Steam Engines and Accessories
(I don't see yours here, but I'm mentioning it for future reference)
(not yours but I mention it for future reference)
Good luck with your quest!
Paulk