1960s or 70s hippie deep purple leather enamel choker

I imagine a hippie girl buying this choker in a west village boutique ???? It’s leather, very soft, suede feel on front. The enamel slider on the front has an art deco Biba feel. I cannot find another online and wanted to see if I was on the right track for period. I bought a box of jewelry at a barn auction in the 90s and it had some junk and some gems like this. Does anyone remember these and where would they be bought and by whom? Thanks!