Aleem -
I have looked through the sources readily available on my bookshelf (haven't done an index search through periodicals) and came up blank. I did find the following two Internet sites, but it looks like you have already mined these:
Aviatik (Berg) 30.40 - fighter
Aviatik (Berg) 30.40
Roman Vasyliev has an entry on the aircraft in his book
Lost Eagles Volume I (
LOST EAGLES. WWI fighter prototypes vol.1), but the information is the same as you have posted, and he uses the same image (perhaps the only surviving image of the airplane).
Roman also produced a 1/72nd model, which I have in my stash. It doesn't show up on his site (
Aviation), but Dr. Zarkov lists it at
ZarkovModels Card Models Store (The Aviatik (Berg) 30-40 model is on the fifth page of Kampfflieger models).
I haven't contacted Roman yet, but he will surely know if there are additional sources of information on the 30-40.
Best wishes,
Don