The marks tell us a great deal! NM stands for Norsk MÃ¸nster, meaning the design is copyrighted or protected in Norway. G-balance weight icon-P is the trademark for silverplate registered by Norges Gullsmedforbund of Oslo, the GP stands for Gullsmed Plett (plate). I believe Norges Gullsmedforbund was originally a trade union of metalworkers, not quite sure how it evolved into a production company. Hopefully another member can shed some light on this.