In response to Ron Guth's query, I researched Robert C. H. Brock in 2001-02 when I was working on the second edition of Breen-Gillio's California Pioneer Fractional Gold (Bowers and Merena Galleries, 2003), because he was one of the few owners of BG-220, the Defiant Eagle 25 Cents (see p. 58). I concluded that he donated his collection in the 1890s or early 1900s; I was not able to learn anything more from the University of Pennsylvania, but Ron might give that another try.

Brock also donated a fabulous collection of Fatimid gold coins, published by George C. Miles as ANSNNM No. 121, 1951. Brock purchased this collection en bloc from Yacoub Artin Pasha, but Miles does not say when. A Google search produces several references to this person, an Egyptian official from the 1880s to the early 1900s, but I found no notice as to when the Fatimid collection was sold. (The collection, long on loan to the ANS, was withdrawn by the University of Pennsylvania when the ANS relocated a few years ago.)