I'm interested in seeing this topic revitalized for my benefit and it seems better to bring this one back from cold storage than to start a new one.
I'm also curious as to the foil of this post's question: Were there European long rifles that seem notably similar to the styles of the various American schools?
It seems to me that many of what we call “schools” of longrifles were regional phases, that developed after first immigrant gunsmiths settled in an area and began work. Let’s take the Bucks County “type”. Verner and Shuler come to mind. Their guns date mostly from 1790-1810. For those who think Wm. Antes’ signed guns or other early gunsmith’s work show strong Bucks County styling and furniture, let’s discuss whether it’s reasonable to expect the styling was imported, rather than developed here.
In science there is the concept of convergent evolution. For example, whales and fish have fins and such. Yet the predecessors of whales were land animals related to the ancestors of cattle. No direct connection between fish and whales, dolphins, porpoises and so on. In other words, similar architecture can develop in multiple places without any reasonable connection.