Thor,
I am not sure all those postings answered your original question. Outside of Maine, almost all the two foot gauge lines that i have ever heard about were industrial rather than common carrier.
There was a two foot gauge paper mill line called the S D Warren Paper Company in Maine. Their two Baldwin locomotives went down to New Jersy and got converted to gasoling engine operation at an amusement park. Now they are on static display at the Boothday Railway Village outside Boothbay Harbor, Maine.
This is the oldest revival of the Maine Narrow Gauge with a group of three or four 60cm Henshel steam locomotives.
Of course you know about the 4 Maine locomotives from Edaville and the one that was in Connecticut; #9 that is now being rebuilt by the WW&F Rwy Museum in Alna.
Ted Miles