Is "N.S. co" mark alpaca? aka "nickel silver"

[torysemo]

Have a teapot, coffeepot, and cream & sugar service set (photo 1) with the mark "N.S.co Silver Mexico" (photo 2). Is this the alloy "nickel silver" or something else? (BTW, I assume that "alpaca" is the same as "nickel silver".)

[AG2012]

Hi,
N.S. is the company name, not nickel silver.
N.S. Co with ``sterling``to compare with.
I suppose you have searched for more marks (e.g. 925).
Have it tested.
Regards

[torysemo]

Thank you. The "co" made me want to jump to the conclusion of a company name, but couldn't find it listed anywhere. Appreciate your help.