Well, that's a good question.
With Old Towns there are 3 grades: AA, CS, and GS (Guide Special) so we are used to saying middle grade for CS. But the Carleton Catalog from 1932 shows only the Carleton Canoe and the Carleton Princess Canoe. Also shown are sponson canoes and guide canoes. The Princess is like the Old Town AA with mahogany decks, seats, thwarts and rails. The sponson canoe could also be purchased as the Princess with all the mahogany.
Dan