Now that I can see the frame in detail, how it goes together, the joint design, etc. I can say with some confidence that this has some definite Swiss design elements to it.

The framing system here is not far from what you might find in the norther art of the Canton of Bern.

And the fact that the bottom portion was clearly used as a milking parlor strengthens this connection to the Canton of Bern, as does the original location in Wisconsin.

Looking through your pictures immediately brought my mind to the impressive farm structures of the Swiss Plateau. This barn seems to have some very clear connection to this tradition.