... I'm pretty sure that the Rangeley Region Sport Shop is still there..
I've fished the Kennebago and Cupsupic rivers, but I think the place to go in the area is the Rapid River between Richardson and Umbagog lakes.
Upper Dam, of course, was the home of Carrie Stevens, so that gives a clue on the popular flies.
My very first fish on a fly, a fly that I "tied" myself, was at Mooselookmeguntic Lake when I was 7