One of our members has kindly sent me this fine photograph of the Royal Arms displayed in the hall of the Palazzo di San Clemente, also known as the Palazzo del Pretendente, in Florence, residence for some years of Charles Edward Stuart.
The legend above the achievement reads:
CAROLUS. III. NAT. 1720. MAG. BRITANIAE ET HIB. REX FID. DEFEN. AN. 1766
Charles III, born in 1720, of Great Britain and Ireland King, Defender of the Faith, in the year 1766