This piece is described as a Fine Diamond-set Gold and Enamel Carillon Music Box and is attributed to maker John rich. Stunning.
From the auction catalogue:
...movement and case marked No. 1, signed and dated on the mainspring by Benson & Ibell, August 1796, playing two tunes on a nest of five bells with finely-chased and engraved gilt-brass skeleton movement, chain-drive fusee wound from the top and eight-step change-repeat cam lever-operated from the right-hand side, in gold an deep blue guilloche enamel case with hinged base and lid compartments, the lid with central sunburst medallion of rose-cut collet and bead-set diamonds with emanating rays and diamonds in quartre-lune formation at the corners...
Learn more about this and other amazing automata going to auction from Skinner's web site where you can download PDF sections of the current catalogue.