Okay, here's my two cent's worth. Charles River builder almost certainly. Given your original description, I thought it would turn out to be. The style of decking is unusual, even for Charles River builders. The peaked kingplank that covers the decking ridge and the peaked coaming (as opposed to a smoothly rounded coaming)- you don't see these very much. I have one that is similar, as does Bill Conrad (not our President, but Bill Conrad in the Boston area). The coaming on the canoe shown here has curved coaming boards that meet in a peak. Both my canoe and Bill's have flat coaming boards that make a straight line to the center. Ken Kelly has a canoe more like yours with the curved coaming boards.
I know of two more in the northeast and I believe one other in North Carolina that is like this one. So they're out there, but uncommon. As for the specific builder... as with all of these long-decked Charles River canoes, there is no definitive answer. See Dick Persson's post in "Wooden Canoe Identification - Companies" for a list of Charles River-area builders, but it is a rare long-decked canoe indeed that was tagged by the maker.
Michael