COMMENTS ON THIS SILVER/NIELLO RING PLEASE. NO MARKS INSIDE

Never seen untill today. Very cool looking ring. And fur sure rare.
Period?
I don�t know, but as told a cool looker!

Why niello? Are the dark places different material?
Maybe better pics possible?

- years ago [10?] when Don was running and first teaching here about the SS Totenkopf Honor Ring this ring appeared.. There were good photos of it.
Better was the owner went to a local military show I also attended and I actually got to see and inspect the ring! He had good provenance for it, was made correctly for the period etc. I can't remember exactly but I believe it had either a content mark or hallmark. Since then I've only seen one other.

I believe the pattern to be an authentic one for the period. That area I believe is or near Stavanger where the Costal Artillery was for the nazis,,and that is the emblem on front.
This ring? can't exactly say,,maybe some more photos,,side, birds eye view ,straight on front,etc.. As usual, well lit, in focus

thanks good gentlemen. I thought niello but maybe it's just tarnish in the recesses; there's a lot of it on this ring!