An Anonymous 18th Century Plaster bust suggested here as the Pugilist Jack Broughton.

    Mid-18^th Century Life Size Plaster bust of a Pugilist?

Perhaps Jack Broughton (1703 – 89) - The Father of English Boxing.

 Proposals for Erecting an Amphitheatre for the Manly Exercise of Boxing, by John Broughton, Professor of Athletics (London, 1743).

 https://bathartandarchitecture.blogspot.com/2021/02/bust-of-moor-by-francis-harwood.html