Folks,
I have followed this thread because I like Eastern narrow gauge and because I wanted to see where it went.
I never did see the magic words, common carrier era, which to most of us defines what is historic in a railroads history.
It matters not how long something a museum has done lasted, it will never be historic: it may be replacement in kind, it may be good woodwork etc.
But I think that the tourist railroad years of the EBT are not what makes the line historic no matter how long they last.
There are getting to be ships, trains and cars that have been in a museum longer than their commercial careers. Being in the museum does make something historic, it is what they did before they got there that matters.
Ted Miles