Yep after the internals and further investigatory shots .. I am in the craftsman/beardy bloke in a shed/ homemade camp as well , it certainly reflects on being European in style , but this doesnt mean its a European manufacturer, more an indication of the major players in that time period WERE euro companies and thats what buildings looked like that they made ..... there are just too many "Non-factory methods " the major one being the window slatting/soldering ... a Manufacturer would have the resources to clean punch windows with a die ...The heavy gauge of the tin and the lack of variety suggests to me that a home builder cut and folded this up out of a single sheet or sheets that they sourced ... even down to the chimney cap being made out of the same mild corrugation material as is the soldered in door frame ... that would be a beeyarch to get right that could be so easily rectified by instead using flat sheet or angle if it were available to the builder ( as it would be in a factory) . Down to the four part base screwed onto the upper base wood ... just steps that speak of someone using "found" objects rather than "provided" ones ...
It's made well , but its not made "Smart" ... as in factory smart ... However a further option might present itself that this item could be a pre-production sample , something made to give the overall look before being simplified and cleaned up for production, but without some form of provenance you could never seriously make that claim it is factory prototype made by a major player ...
However dont lose sight that this is a charming piece and should be celebrated as such... its pedigree with nothing to support it , is relatively moot ... it is what it is , and can be whatever you want it to be, but you just cant prove the pedigree without being able to compare it to another or without documentation . In the present scenario with neither its just more in the home-made camp than factory in my eyes .. you can see the opposite , and thats what makes the world a great place
It exists ... and thats a good thing hey ?