800 Silver and Polychrome Enamel Butterfly buy Pin, Rollover Clasp, Signed JS BC

Beautiful, dynamic silver butterfly carefully enameled in shades of blue, orange, yellow green and purple. This is signed, with what looks like JSBC, but we can't identify it. Likely 1950s or 60s, almoat buy certainly European. This was given a light polish, but there's quite a bit of patina, and we don't think it was ever meant be really bright. Marked 800 SJB4