Pretty sure it is a Tremblay that has been modified. Seat construction, seat mounting, hand thwart, single center thwart fastened with 4 bolts, lack of tumblehome and ribs all look to be Tremblay style. The original crescent shaped decks appear to have been modified to copy early Chestnuts. The center thwart and floor boards are not original. Though not likely, if it still has the original canvas it should be Verolite. More pictures would help.