One of the pole end types the Hudson's Bay Company used was a simple piece of steel pipe, fixed to the wooden pole end with axe-head technology.
There are some replica poles with this detail at the Peterborough (Ontario) canoe museum.
A stop at Home Depot got me 12 feet of 1-1/4"OD closet rod, two 2" long pieces of 1" Schedule 40 black iron (I suppose galvanized is ok too - it won't matter much) pipe and a couple axe head wedge kits.
The 1" pipe has an OD of 1-5/16", a little bigger than the closet pole OD, but the small out-step doesn't seem to be that big a problem.
Schedule 40 pipe isn't that hard to hacksaw, but, if you can, get the store to cut the pieces for you on their pipe cutter. You'll have to deburr the ends with a hand file, but you won't have to worry it square.