Sorry Doug, misunderstood your thrust.
If the goal is to increase revenues through ridership or special events, it's far more cost-effective to build revenues through addressing the non-railfan market, which by all accounts makes up 90-95% of tourist railroad visitation. There's no evidence that Soccer Mom from Albuquerque or Fort Worth knows the difference between a C19 and a K37, or would care if she did.
As to the timing of RailFest, it's planned at a time ridership on the D&S (and the C&TS, for that matter) is low, and the existing employee base can handle the additional workload. Planning it in July would drive costs up (overtime, temporary employees, etc.).
And according to what the folks at the D&S told me last year, RailFest is at best a break-even proposition, and probably lost money in 2000 when all costs were included.
That doesn't mean special events can't generate money, but they won't generate higher margins. The best year's take on special trains on the C&TS was in the early 1990's and total revenue was about $50,000 (profit would be less than half that). Building ridership by 10 people per day will exceed that revenue significantly, and won't raise the cost of operating the trains by nearly as much.
Once revenues are where they should be, and the equipment is back in good shape, then railfan-oriented events will be easier to schedule and operate. They're good PR, but we'll never depend on them to make the difference between a good year and a bad year.
JAC