Hallmark on Silver Enamel Butterfly Pin

[dcpaap]

Hello all... I have a lovely butterfly pin here. I am not computer or internet savvy, so I am feeling quite accomplished after figuring out as well as the copy and past thing. Yay! I need help with these hallmarks. I have done some research, and discovered that it may be from the Scandinavian area.
The mark 925S, was a clue that sent me to the Norway, Sweden areas. The middle symbol is the most perplexing for me, as well as the last two marks, NM. I have searches for hours, and days! I could not find anything like this. Please help! Thanks in advance!

[Qrt.S]

Your butterfly seems to be made in Bergen, Norway by Theodor Olsen during the first half of the 20th century. The company is still active today http://theodorolsen.no/om-oss/

[Qrt.S]

Forgot the NM. It is an abbreviation of "Norskt Mönster" meaning Norwegian pattern. It is a kind of a trade mark for Norway.

[dcpaap]

Thank you Qrt.s That was fast! And I'm getting close to solving my mystery. Would you know what the center symbol means?

Kind regards...

[Qrt.S]

In my eyes it looks like a crown on Bergen's town mark after 1842 that is 7 cannonballs in two rows of 4 and 3, but it is only my opinion.

[dcpaap]

To Qrt.s
Thank you! Have a wonderful day!

Kind regards always,
Cathy

[Tosten]

It is not a Crown.
It is M and A. Magnus Aase.