Vintage Mexican Sterling Articulated Fishbone Necklace Moveable Pre 1970's

Mexican Sterling large fishbone necklace with fine detail, smooth movement and a quizzical look. Pre 1970's mark. Head, bones and tail are linked by chain, connected to each piece giving independent movement. Sweet quizzical look on his face. Signed: Double stamped Hecho en Mexico 925 and eagle mark 1? Chain is unmarked and is not worn in any way, but clasp looks like it might have been replaced. Size: chain is 20 in. pendant 3 1/2 in Condition: very good vintage, some tarnish