No. I assume you mean Rocky Mountain fur trade. The answer is still no. The adjustable rear sights are a newer invention. Every sight that I have seen on a period gun has a fixed rear sight. Also, most shooting matches specify fixed sights. you really don't need adjustable sights. Work up a best load for your gun, then move/file your sights to shoot point of aim or 6 o'clock and you're done.
Why would you want them? All adjustable sights become fixed sights at the time you use them, The exceptions are those vertically adjustable for different ranges. For that, folding leaf sights were developed , which are another form of fixed sight.
The military didn't go to adjustable ladder sights until the later part of the 19th century, after fixed ammunition became the standard. That was primarily for their use in extremely long range use, and area intended volley fire--creating something of a "beaten zone", or area denial in their collective application. Most state game agencies frown on the use of area weapons in sporting activities.