Metamorphic library steps of a very similar type seem to have been a speciality of François Hervé (fl.1781-96) and John Meschain of 32 John's Street, off Tottenham Court Road. A set with an engraved brass label was sold anonymously at Sotheby's London, 7 July 1967, lot 167. The label is illustrated in The Dictionary of English Furniture Makers, Lees, 1986, fig.43.
Another labelled set is in the Victoria and Albert Museum (w.7-1932) and is illustrated in D. Fitzgerald, Georgian Furniture, H.M.S.O., London, 1969, no.130