I know this is a long shot...a very long shot...but thought I might give it a whirl. Something may come of it.
I attended Cornwall Comprehensive (Dortmund) in 1971 or 72, just in behind Napier Bks as I recall (and across the road from a 'friedhof'...cemetery...we 6th Formers often nicked over there for a beer and a smoke at lunch).
I was the only Canadian kid in the school and felt a bit out of it at times. I hooked up with a fellow by the name of Derek Wilkinson, who was a boarder at Cornwall (home on weekends). His father was a Major, I believe but I can't remember where he was stationed or even what regiment or unit he was with. Derek and I were best friends and his sense of humour was more akin to mine.
I think we did write a bit after I returned to Canada but that faded away and we lost touch. I'd enjoy hearing from him if his name rings any bells for anyone and they have any contact info for him. I'd guess he's at least 53 to 55 by now. Yikes