I made a copy, from some linnen canvas I had laying around . It is a great canoe pack (IMHO), with space for plenty of stuff inside. If you fill it with food and stoves you will break your back, but with a reindeer skin -- packed waterproof! -- a blanket, a tarp and some spare clothes as well as the pot, axe and food for a week it is quite ok on portages, and packs neaty into the canoe. As to the canvas in the wet, Bill Mason made the observation that it will dry out on it's own, which is more than a totally waterproof bag will.
Not a waterpoof bag, no a bag for long portages or hiking, but quite nice on most canoe trips.
On some of the trips that I've been on a canvas pack ( and it's contents ) wouldn't have the chance to get dry.
I've also read lots of historical reports that complain of soaking wet gear, stopping on dry days when they could have been paddling to dry their gear, and having to lay branches inside the canoe to hold the packs out of bilge water caused by rain or waves.
Where they do score is something that you mentioned above, how neatly they pack into the canoe.
