I had trouble finding one too when i changed my seal at the transmission output... It also had to be thin walled, which was even harder to find.
I ended up buying one at canadian tire and I trimmed it down on a bench grinder.
Canadian Tire doesn't have this size in their usual Mastercraft section, but their's always a small Powerbuilt section and they do have 32 and 34mm 1/2'' drive. You'd have to check if their deep enough...
So double check with canadian tire : search 32mm axle Nut Socket