Hi Chris,
The trapezoidal stern seat, the stem profile (wider than in an Old Town), and the serial number font and size are consistent with Rushton. The half ribs seem similar to ones in some later Rushtons, but I don't have photos handy. The treatment of the top of the outside stem is odd, as is the tip of the stem band but because the screw through the stem band into the deck is an obvious replacement, maybe some modifications were made by a previous owner. The two thwarts are distinctly different from each other, so one is probably a replacement (the bow one looks like those in early Old Towns; the stern one reminds me of some I've seen in later Rushtons).
Michael