Hello,
There is one, repeat one, photo of
Erich Loewenhardt taking a
Jasta 6 Fokker E.V for a test flight. In JG I, Jasta 6 was the only unit to receive Fokker E.V's, and they didn't fly them for long. Apparently, Loewenhardt, the commander of Jasta 10, took the opportunity to test fly one of them. The photo shows it in flight, and in full classic Jasta 6 markings.
The Roden company took their inspiration from that one photo, and marketed their Fokker E.V model as "Erich Loewenhardt's". But he was
only giving it a test flight. I'm reasonably certain that he never flew the type in combat, and he certainly did not score any victories in the type. Jasta 10 was never equipped with any E.V's.
In fact, as you note, the only confirmed victory we know of for a Fokker E.V is Emil Rolff's victory of 16 August 1918 (a Camel at 1230 hrs, near Mesnil) - that is described in
Richard Wenzl's book
Richthofen Flieger. Ironically, Rolff was killed due to wing failure of his E.V only three days later - one of the two fatal accidents involving E.V's that grounded the type.
I can state pretty confidently that Loewenhardt's victories in the summer of 1918 were all scored in various Fokker D.VII's. Once he had a BMW-engined D.VII, he wouldn't have bothered flying an E.V in combat at any rate.
By the time that any of the re-designated Fokker D.VIII's (D.8's) with newly-reinforced wings, etc arrived at the front the war was basically over. As Peter Grosz stated in his Fokker E.V/D.VIII Datafile, it's unlikely that any Fokker D.VIII's were used in combat in WWI.
Sorry, but those are the most likely facts.
Greg