Photographs of the Sotheby's Marble Bust and the Grimsthorpe Castle Terracotta Busts of Handel
All by Roubiliac for Comparison.
Malcolm Baker had problems with this bust but I can find no reason to doubt the authorship of the Sotheby's bust.
My blog entries on the subject should be enough to convince any doubters!
Above The Grimsthorpe Terracotta, and the Sotheby's Marble,
Below the Handel Haus Plaster and The Gloucester Cathedral Plaster.