A bit late, but browsing the web, as you do when nothing better comes to hand, I found a reference to MI 14.
One of MI14's most valuable sources, codenamed COLUMBA, consisted of reports returned by pigeons dropped over Nazi-occupied countries in packs
containing a miniature spying kit.
Some time after the war, MI14 became part of MI6.
I like the idea that a Royal Surgeon was somehow involved, maybe reporting back on a member of the royal familly involved in some forward action?
(thoughtsfull 6/11 ) found a possible link to the message sender, "Major-General (Sir) Arnold Walmsley Stott, KBE, FRCP (with extra t) was
(Serjeant)Surgeon to the Royal Household and Adviser in Medicine to the U.K. Emergency Medical Service during WW2."
edit on 1-12-2012 by dowot
because: Adding ref re Stott
edit on 1-12-2012 by dowot because: Adding posters name and date.