costumejewelrycollectors.comFrom 1937MBMB with the Phrygian cap was used in 1937–1949 and later when space was limited.
costumejewelrycollectors.comFrom 1955BoucherBoucher preceded by the copyright symbol was used from 1955 onward.
costumejewelrycollectors.comUndatedMarbouxDolan found registration in 1937; Brunialti found first use in 1955 for a less expensive line.