Hi Loo,
Yes, it was wonderful to find the information I have found so far, but as is always the way we still want more. We hope to join the anglo-german fhs this year and perhaps that will give us some more information.
As Johann was from Germany, I found his details on the german wargraves site. From what i remember it took a bit of time to figure out how to search as I don't have german, but I did find a site somewhere that gave advice on how to search the site.(
http://www.axishistory.com/index.php?id=3595) If your man was german perhaps that could be of use to you.
As you are compiling a list of internees, I have another name for you, Peter Solyts is mentioned in some of the documents as an internee who was also arrested in Liverpool in May 1915, also sent to Stobs and then to Knockaloe, both he and Johann are mentioned in the letter as deceased prisoners of war so I assume Peter also died in the camp.
I will pm you with my contact details.
Best of luck with your project,
Michelle