Further update, 
 
The crown M marking ties in with German naval markings from WW1 (the M denoting Marine, in conjunction with the crown of the Kaiser 1871-1918) 
 
The use of such leatherwork, gathered/salvaged from the beached German ship, would tie in with Kronckew's attribution. 
 
Exciting stuff!!
		 
		
		
		
		
		
		
		
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