Thanks to all of you for the compliments - I am pleased that you all like it as it gives me an incentive to continue.
Xmald: it seems to me that the confusion and uncertainty is not confined to Etrich Tauben - it seems to apply to most early aircraft. These machines were hand built to an individual order, with the result that customers could specify what they wanted, or the manufacturer decided that an upgrade would make a design better, or someone else decided to add/subtract a bit….and so it went on. Mass production did not really begin in earnest until 1915, and until then there do not seem to have been standard drawings or components. T. Sopwith, in an interview with R. Baxter, said that his early machines were built in the workshop without engineering drawings as we would understand them - they were simply put together according to some specific requirements, span, chord, length, etc, and some general drawings, but quite a lot was left to the craftsmen and then adjustments were made when the aeroplane was wheeled out and tested. The use of different engines was commonplace, and nobody seems to have thought to keep accurate records of all of the variations and variants for the benefit of later modellers and historians.It was the need to mass produce that caused the changes which led to standardised components and designs, and then to systematic classification and typologies.
There is also a problem that early photographic records are not always reliable as sometimes information about photos has been lost. Add to that the fact that company records have also been lost or were somewhat incomplete and you have a minefield for the unwary or those who want to be very certain about something. Different sources will tell you different things about the same incident/machine, so as always it is best to go to the original sources if possible. That is not possible for me so I rely on the accuracy of others, but even then I cannot be wholly certain. Given the circumstances, I think that we do reasonably well, even if we are still confused at the end of it!!
I did not know that only two Etrich Tauben were used by the German army - they certainly used Tauben from other manufacturers. I suspect that it was the underwing spars which made the aeroplanes difficult to service and reduced performance that was the problem. One source I have seen claimed that the spars were removed in service, but I suspect that this is an error and that this has been confused with a Taube from another manufacturer who did not use the underwing spars, but I cannot prove it. The German army did not like several aircraft types and refused to use them, even though the owners offered them for service use. I have based my markings on a photo of an Etrich Taube that did not carry a serial on the fuselage but had the wing crosses without the white squares. What the engine was is impossible to tell from the photo.
Thanks for the link by the way - I have been sneaking looks at your wonderful build as I have been going along - just hope that when mine is finished it will be nearly as good.