A completely original Albatros DVa exists at the Smithsonian instititute. There is also AFAIK an original one at the Australian War Museum.
On the other hand, there is no original DIII in existence.
a) A DIII cockpit would be very similar to the DV and DVa.
b) WWI Aircraft of the same type often had different cockpit layouts, especially if they were manufactured at a different workshop. (no mass production, remember... Henry Ford was yet to invent the assembly line)