Spent quite a bit of time looking for sources, but yours seem to be the best.
You posted a bunch 'o photos, so thanks for all the research that you did.
Actually, my version will be a little weird and this mine serves a Gn36 road.
To get the right scale I used some code 210 rails,
and since you can only see 10" into the mine shaft which exits part way into a hard rock tunnel,
I have angled the rails to create a heightened perspective.
Gauge is 13/16ths at the deep end of the shaft and 1 1/4" at the opening.
It will be fun utilizing your ideas, but I'll have to skip your beautiful curved spoke wheels.
I used to be in the cast iron foundry business,
and I strongly approve of the curved spokes,
which reduces stresses on the wheels as the iron cools.
Your skips will last forever without cracked wheels.