Found it, just had to look in the right book: it is an Autenrieth body. But reading the text more closely, the author says that he doesn't have an original photo of the Autenrieth-bodied Fafnir, so he is showing a similar body. That would open the question again in so far as the puzzle car has a standard body offered (not built) by Fafnir, which makes me think of Miesen again.