N.S. Meyer sterling screw back unknown date?

[TreasureHunter]

Got this the other day from an antique mall, looking closer it looks like the N.S. Meyer shield and it does say sterling next to that. What era is this? Value?

 

Thanks

Bill

 

 

[TreasureHunter]

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[TreasureHunter]

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[Brig]

the 210 marks dates it to the 50's

[Brig]

Stumbling back on this as I sort the EGA reference...and just noticed that someone added a fouled rope to the anchor...perhaps done during the transition circa 1960