Took a trip up there in '12 and camped at the outlet of 5th Machias. I don't know the spot you mention by that name. We got there late in afternoon and camped beside the road, within sight of the outlet, and that is from where we launched our trip the next morning. Sorry, I don't know the name of the place. There were no buildings within sight. And we didn't actually paddle more than a few strokes on the Lake.
Suggest you run your own shuttle. I thought the price of shuttle (from the commercial outfitter in that neighborhood) was beyond reasonable.
Heel and Pegpads™