Please Help ID This Heavy Antique Silver Brooch

[cap]

I found this brooch at an antique show this weekend. It measures about 2" across and weighs 39 grams. It tests positive for sterling. The only markings are the initials on the back. I can't quite make them out maybe MNN or TTNN or NNW?? Does anyone recognize the mark? I am assuming its European, due to the design. Does anyone recognize the style?
Thanks!

[JAKJO]

Hi Cap,

"TINN" is Norwegian for pewter.

Best regards/JAKJO

[cap]

Thank you. I am aware of that. At first I had considered that possibility, so I tested the brooch for sterling and the test was positive. I don't believe the mark is TINN, but something similar.

[admin]

Hi Cap,
Many alloys of tin, including pewter, do not react to acid testing in the same way that nickel and brass do. Suggest you find a piece that you are sure is pewter and test it, you may be surprised at the result.
Regards, Tom