Agree that Alna Center is the best and only place for special events. This discussion is more about what we can do moving forward to make ToM a "destination" as described by Steve.
... Start working on Temm's Shingle Mill and the To-Be-Named / Morse Sawmill.
Like Jason and Steve are saying, having an interpreted, working shingle and saw mills operating at TOM are a destination unto themselves.
Getting the railhead back to RT 218 and putting an Alna Center-sized "Trout Brook" station there coupled with the Midcoast trails will provide another destination with a different theme.
Alna Center, in addition to "large", flexible event space, could be use to interpret how the local farms leveraged the existence of the railroad. Yet another thematic destination. The WW1 reenactment is a perfect example of the event space flexibility.
Finally Sheepscot, standing in for the Wiscasset yards, gives a railway-based thematic destination.
We use the railway as a method of transporting the visitor to the particular thematic area they are interested. Maybe a visitor getting on at Sheepscot Station and really wanting to go take a walk on the trails at Trout Brook Station, sees all the interesting stuff at TOM Station and spur-of-the-moment decides to get off and spend time there.