Per Ned Roberts (The Muzzle-Loading Caplock Rifle) there were several manufacturers of trade guns who used the sitting fox, facing either way and it seemed to make no difference to the trade. Howsomever, that was written in 1940 and newer archeological/anthropological information may ahve given the lie to that statement.
~Kees~
Dang,.... I'd been working on my findings in
FIREARMS of the FUR TRADE by James A Hanson, for over an hour, and "POOF" it all just disappeared.

So,.... I'll just summarize a bit of what I found, by saying it appears,.... Thomas Barnett started the North West Company and was making North West Guns around 1789. He also
imitated Hudson's Bay Company's "fox-in-tombstone" and used the same mark on his guns in addition to using the initials "IB" under the fox. This mark continued to be used on the North West Company's "Barnett" trade guns by Thomas's son, Robert Barnett, who added "R. Burnett" to the tail of the lock until around 1820.

There were many companies making North West trade guns over a period of about 200 years and well into the "percussion era" with (somewhat) minor differences, and with "foxes" looking (both) "east and west".
After checking this
huge 580 page book that primarily concentrates on North West Trade Guns,.... I can find no reference that uses the word "counterfeit", except for Hanson's usage of the word "imitation" mentioned above.
