Hope DTG is considering different steam engines from different countries. The US would be a nice start.
Hagen-Siegen in steam era would be amazing! There was a poster on SoS with a BR23 on it, maybe a teaser for whats coming...
From Australia I would love to see Queensland PB15 class locomotive Queensland C17 class locomotive Queensland Beyer-Garratt class Queensland AC16 class locomotive Queensland BB18ΒΌ class locomotive
I suspect for Germany it might have to be something current, not knowing how difficult the research would be for a historic route in the same vein as SoS or PFR. The one that immediately springs to mind is something on the Harz network, probably the Brocken Line. Would love to thrash those massive tank engines up to the summit.
West Germany DB BR010 Frieda and her GDR lookalike the 18 201. Heavy mountain grades DB BR085 095 086 (TSC Wutachtalbahn wiki german link) GDR 95.66 65.10 US Big Boy home route Sherman Hill UK Ivatt 2-6-2T Arthur Caledonian Railway 812 Donald and Douglas SR Q1 Neville 4MT Belle