Okay I'll take a stab at it:
You said...A couple of things to solve:
1- How to convince the Commission that this doesn't violate the sacred "equal service from each terminus" policy.
Answer---The engine originated on the passenger train in Chama. Maybe they can get away with that one. Or, maybe they can call it a work extra.
Answer 2----If the idea pans out maybe offer some similar trips from Antonito to Osier and Back, solving that problem, but creating another one---deadheading an engine and train to and from Antonito(Helper not needed there of course)
Answer 3---Do away with this stupid law if you want to make a few extra needed dollars to help keep this fragile piece of Railroad in existance.
2- How to turn an engine around, as the loop at Osier is not usable.
Answer---You got me here Jay. I was counting on it being open.
Answer 2---In light of this I would turn the engine at Cumbres like normal. Pull the train tender-first to Osier,run around the train, and do all the photos going west in the afternoon after the Pass. Trains are clear. Then at Cumbres the engine stores the cars and heads home. In this scenario the caboose never needs to be switched, unless you want to take it to haul rides up and down the hill each time.
3- The minimum passengers needed. Deciding at a late date that are too few passengers will just create a PR disaster. You have to either run the train whatever, or not run it at all.
Answer---You have a valid concern here. I never said I had all the answers. However, most of the types that would do this might be more of the railfan types or quasi-railfans so they would be more forgiving(maybe!!!!).
Answer 2---When we ran charters we always stated a date that the trip would run or not run if a certain number of tickets were not sold. In this case, I think riders would have to be given a 5 day cut-off or something like that. If not enough reservations were received by Previous Monday, then scrap it. The folks will have to settle for the regular train options. At least they would get some notice. Also if you set the break-even number low enough, you might pick-up last minute folks just by allowing the train to run on marginal sales. Especially if folks riding the Saturday train(Pass)saw the freight and decided to ride on Sunday(given availability).
More likely I could see groups of fans wanting to do this, say the week of some special event, or work session. It would not compete with other charters since it only covers one portion of the line.
Answer 3-By limiting the number of days it runs(saw once a week), you funnel reservations to that time, and in theory create the one day there should be enough riders.
The costs of all this are minimal. Pay the engine crew a full day instead of helper day. Add the Conductor and Brakeman and some coal for the few extra miles.
I bet if this were a regular option you could get some great PR out of the rail magazines, as well as the local press, since this could be another way to interpret what the railroad was really all about. I would invision a train made up of all different types of rolling stock for this purpose.
On days it is not used it is on display at Cumbres. Train crew could hang a nice banner or sign on the car nearest the crossing for C&TS advertising as well. At least the cars might get a little use this way as well.
Greg Scholl