Narrow Gauge Route Ideas: -White Pass and Yukon -Cumbres and Toltec -Durango and Silverton -Ffestiniog RR -Welsh Highland RR -Talyllyn RR Steam locos needed; WP&Y, C&T, and D&S have diesels too
Ffestiniog Railway would require DTG to dust off steam traction which seems unlikely, given it didn’t even rate a mention in the Direct presentation. There would be the added complication of adjusting the current very flawed physics to deal with the oil firing predominant on the FR. And if they were going to do this route, then makes absolute sense to also include the Welsh Highland Railway.
The kemsley light railway (ex bowaters) would be a nice simple route to make a start on. They have a couple of diesel units if steam is off the cards.
Another NG line: Harz Narrow Gauge in Germany. The Harz line uses steam power too, so it probably won't happen.
But they also use railcars do especially on the selke valley railway, but it would still feel empty with out steam