Nice! That is a treasure!
I remember as a kid visiting a friend who lived on a farm. In the barn, his dad handed me a knife to check out, it was used for opening feed sacks. Crude home made handle fashioned from a stick cut from a tree, dark old thick double edged blade about six inches long, stained and pitted, ground edges and very sharp. I thought it was cool but asked about how come it was looking so rough. I was told that it was Roman and about two thousand years old, found on the farm.
Just think of the age and the miles that Trade gun has traveled. A musket going on two hundred years old is allowed to look two hundred years of age. I think of it as a beautiful antique not as a rough shape deer gun.
If it were mine, I would have a huge dilemma on my hands. The conservator and historian in me would want to leave it pretty much as is and just preserve and conserve. The restorer and tinkerer in me would want to take it apart and gently clean, check out and record every marking on it. Research and identify the makers of the parts and about whoever assembled it. Then the history of where it went, who owned it, where it might have been. Maybe even getting everything working. Do some gentle shooting.
What I have learnt over the years, is that if in doubt about doing something, such as cleaning, I just don't do it and wait. Once something is done, its done. I have a couple of uncleaned untouched Nepal muskets hanging on the wall calling my name whenever I walk past. Had them years, still untouched.
If I do work on a project, I try to remove signs of abuse and neglect, but leave the signs of age. Honest wear looks fine in my eyes.
Funny how so many old forgotten arms get propped up in the corner somewhere and end up getting splattered with paint from somebody decorating the wall or ceiling. Little dots of white paint seems to be a popular theme.
Trade guns have that large trigger guard, which I have been led to believe is for use with a gloved finger. Canadian eh?