Thanks to Archival Clothing reader Murat for directing me to this current ebay auction for an 1882 Duluth Poirier packsack. According to the seller, the three stitches on the front flap of the pack may indicate that the pack is a rare, original Duluth prototype (thus justifying the $100k Buy It Now option). The seller also directed me to a Duluth Pack youtube video featuring a canoe pack similar to the one up for auction. Side note: I never thought to search youtube for archival footage of historical canoe packs.
1882 Duluth Poirier Packsack (via this ebay auction)