Please help identify maker of unusual Norway filigree pin.

[hiohsilver]

I was surprised to see Norway - the 3rd word - on back of this lovely filigree pin. It also has initials H.O. and the word Sterling. Can anyone identify the maker, and perhaps give a time frame of when it may have been made? It has an interesting old tube hinge and is very sturdy. Thanks for all help, past, present and most likely, future.

[bukkus]

H.O. is listed as Kari & Henning Oddershede, registered in 1974.

[hiohsilver]

Thanks very much for the info. I posted the question awhile back and I'm delighted over receiving a reply. I knew one would come sooner or later. I will make note of it. This is the second piece of jewelry I have come across with this mark. Thanks again!!