[Robert] Brough’s life was cut short during a steep upward career trajectory; he was very much a rising art star, working alongside Sargent and having recently been made an associate of the Royal Scottish Academy.
There are 3 known full size versions [of this work]; National Gallery of Scotland, Aberdeen Art Gallery, and the third is believed to be in a private collection in the US.
~FROM Lyon & Turnbull | Online Auction Specialists

Bust of Robert Brough by Francis Derwent Wood, c.1905 / Bronze / Image from National Galleries of Scotland, Edinburgh, UK