[Simon Schatz]

Ed, that’s true. I repeated known facts and added a little bit more. The reason why some of the planes had one kind of markings and why other planes had other kind of markings will get explained in the book.
Why should I not use the word “theses” if I refer to your reply? The “Serie/Zelle” system, that I BTW have discussed with another historian before you have written it here, maybe fits to Junkers, but it’s your “theses” that it also was used for the Dornier Do 335. Do you have the convincing proof without any alternative interpretation? That would be a List of Batch no./fuselage no. and the respective W.Nr. If that internal list does not surface there is no striking evidence and the connex remains an Interpretation or a working hypothesis. So your “theses” is at least an “enlightenment” or better said a confirmation that it was used by Junkers and other companies. That’s useful I think – thank you for that. May I ask when your book will be ready for publication? The chapter sounds very interesting.
BTW: The background about the double tail markings also couldn’t get answered by Dornier employees that were interviewed by different historians in the past decades. About 90% of all Do 335 documents were destroyed or were lost in the chaos of 1945. The remaining documents, and the fact that nearly all of the guys who were involved building the Do 335 have passed away, makes it quite impossible to answer all questions.
Maybe, with much luck, documents will surface, and answer the such open questions.