Hello Kai,
spot on regarding D-EBEI.
Let's put it this way: Since there are no two even loosely similar Bf 108 these days we use D-EBEI as the base.
The landing light for instance is not present on the real D-EBEI so the exterior model is a mix of various features if you will.
I don't think that we'll do a fixed pitch prop version since that would require an entirely different set of airfiles.
There'll be a modern and a vintage style cockpit though.
The planes we are looking at as reference are the three "prominent" planes located here in Germany, that is the privately owned D-EBFW,
D-ESBH of the Messerschmitt Stiftung and of course Lufthansa Stiftung's D-EBEI "Elly Beinhorn".