Community,
Here is a cover from Newfoundland that I can't figure out one piece of a puzzle.
What I have discovered is that this is postage paid cover from a naval base called Avalon near St Johns sent on Nov 16, 1943 to Ottawa. The blue triangle cancel is almost certainly 65 mm. According to Walsh & Butt's NSSC it is the PP9d cancel.
The back has a blue cachet from the "Naval Store Officer/Dockyard".
What I need help deciphering is the envelope : O.H.M.S. is obviously On Her Majesty's Service and quite common. But what is the caption below that : " S. DE S.M. "?
Strange. I can't find anything on it. Appreciate any information
PS Thanks to the advice about cropping the image. Hope I did it right
