Thank you for the explanation, and for the fact that most of what you said matched most of what I was thinking.
Many years ago, when I was a grad student at Indiana Univ, a recent graduate of the music school ran regular showings of silent movies which he accompanied on the organ. A group of recent grads and current students developed a tradition of going together, and when the guy who had been coordinating these parties became tired of doing that, I agreed to do the job. It was a mess!! I hadn't realized how many times someone might want to add 1 ticket or cancel 1 (our tradition didn't include much in the way of deadlines and I didn't realize how important one would be). By the time the show finally occurred, I had completely ruined at least one or two previous friendships.
I have been thinking of that experience as I read through this thread. I suspect that running an excursion is much more effort than most of us can imagine. I suspect that the current economic conditions have greatly increased the economic risk of that kind of operation, leading the owners to want to put enough time between excursions to build enough "hunger" that ticket sales will exceed the cost of the excursion (they have already put blood into the restoration, we can't expect
them to incur addional cost so that
we can enjoy the ride).
I would assume the best time to run an excursion would be during some holiday to limit the amount of vacation time needed to ride (this would be one way of increasing the headcount above the level consisting of fanatic who will come anytime at all), but working that out with the host railroad could make the task even more complicated since they would have fewer cars available to put behind the locomotive.
In short, I greatly respect what the 315 group has done, and I chose to believe that they are making best use of it.
