I have a beautiful 3 view print of the D-III / D-IV. (no not a picture) This is a scale wire (blueprint)diagram that clearly identifies all construction details. Unfortunately it's drawn on 2 sheets that are roughly 24" x 36" each. I also have the same type blueprint of the Siemens-Halske Rotary engine. (it's my intention to build a R/C Model one of these days).
If you are interested I can try scanning these in sections or photocopying and then mailing to you.
-Thomas -
Conquistador_del_Cielo@Yahoo.com