In her ‘Dictionary’ Jackson records an engraving of a drawn profile of George III, inscribed ‘Drawn, engraved, and published by HWH, 24, Clerkenwell Green, London'. Later experts have presumed this to refer to the artist HW Holden, a profilist, engraver and print-seller known to have worked from 24 Clerkenwell Green, London 1809-1810 . Indeed one of Holden’s prints is very similar to the example recorded by Jackson. However, there are no existent silhouettes or further biographical information to verify this connection.
Source: McKechnie (Author of, British Silhouette Artists and their Work 1760-1860)
Holden, H. W. (McKechnie Section 2)