All that is known of W Kempton is that they were the artist of a posthumous print of Francis, 5th Duke of Bedford. It is presumed that Kempton was the original painter and engraver because it is their signature that appears on the silhouette.
Source: McKechnie (Author of, British Silhouette Artists and their Work 1760-1860)
Kempton, W. (McKechnie Section 2)