Well, hmm....
I'm not going to say "it's a bad idea," it may be a good one. It's certainly original enough, however...
For the WW&F, the train itself is the ride/attraction, and as such does it's share of fundrasing and interest-generating. I have to stretch quite far to see bringing in a "kiddie ride" to attract folks who already come from miles away just for the train.
I DO think, however, that a musical event such as a folk/blues festival out in, say, Albee's field might be a more attractive option to the RR, as folks could take the train out there and back, and/or park near or at the field.
It's an idea, I'll leave it at that.