Paiute Tribe of Pyramid Lake

I have the opportunity to purchase these pieces. 3 Brooches 1 Bracelet. I was told by owner that they were purchased at the Pyramid Lake Reservation late 60’s or 70’s. None of the pieces have metal markings. Could these be silver or nickel silver? There is a very faint almost unreadable mark on the turtle but I think it spells Sterling. There is also an extremely faint scratched mark on the oval floral brooch looks like script 30. Other than mentioned, there is no maker’s or artist marks.
Any info would be appreciated.

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