After a couple of weeks out of action after a knee op I was very interested to see this thread as the last issue of 2015 of
The Formation Sign Journal of the Military Heraldry Society included an article of Scout Badges with military origins, a copy of which is attached.
The details provided by Blackpowder 44 make a fascinating addition.
Go to
http://militaryheraldrysociety.com/ for details of how to join.
Jon