The "Mercury Deluxe" and "Mercury Utility" were shown in the 1941 Peterborough catalog and the "Mercury" was shown in their 1954 catalog. I'm not aware of any detailed serial number records for Peterborough boats so more detailed information may not be available. The Peterborough catalogs at http://www.wcha.org/store/canadian-wood-canoe-and-boat-company-catalog-collection may help. Good luck,
ACBS are the folks who put on the annual wooden boat show in Muskoka and they may have a lot more info on the various wooden ( and gah!!! fibreglas) runabouts that Peterborough and Chestnut built in the 50's and 60's.