I didn't say anything about expecting "exact" or "carbon copies" of this panther image in the eighteenth century. But the only evidence for how eighteenth-century men (such as Albrecht) would have represented a panther is the range of ways that (other) eighteenth-century men represented panthers. How a twentieth-century logo represents it is irrelevant and, as I said, may raise more questions than offer answers.
The engraving on the rifle and the "modern" Shawnee panther are very, very similar--in the spread of the legs, even in the dip of the head. Such a similarity, I think, needs to be explained. It could be explained in many ways.
But if this particular way of representing a panther is only a twentieth-century phenomenon--and I don't know that it is, just asking--and it also appears, perhaps uniquely, on this eighteenth-century rifle ... well, as I say, I would think one would need to explain that. One explanation is that the modern Shawnee panther derives from this eighteenth-century rifle. I doubt this is the case. So how else might one explain it?