I tend to agree with you on your conclusion about the Tallyllyn vs Edaville. Even though Edaville came about before Tom Rolt and volunteers started in, the TR is still operating uninterrupted on original ROW. That's pretty amazing.
Edaville was basically the B&HRR transplanted to Massachussetts. With a little bit of SR&RL and Monson RR thrown in.
Too bad the good folks of Bridgton weren't willing to hang on a few more years.