Wrong time frame but here are a flintlock pistol, long rifle, and shotgun:

http://homepage2.nifty.com/~mr_trout/models/poserModel.html#Weapon

and another rifle here:

http://www.renderosity.com/mod/freestuff/search.php?section_id=-1&query=colonial

There was a free blunderbuss somewhere, but I can't find it now. If I remember correctly, it was not easy to find in the first place, and I lost it in a HD crash.