Inlaid disc brooch

Jewelled silver disc brooch (Frankish), diam. 2.7cm. Constructional details obscured by wax used to reinforce it, but eveidently it had an iron or iron and silver backplate, and a silver rim enclosing silver cloisons set with flat garnets on past backing and chequered gold foil. Pattern of two concentric circles inside rim, divided by straight cloisons, 8 dividing outermost sector, 4 the next sector, but cloisons staggered. In centre, a tiny roundel set with cabochon white paste(?).On Mayer card: M 7277?It is clear from the Gatty Slip that this object should be M 7277, not M 7275A as catalogued on the Mayer card and repeated by SCH. – B.B.