I have a few family photos from Henry W. Biffar and Silkworth Studios. Here are the addresses I have and best guesses re dates of the photos:
Silkworth Studio, 261 Manhattan Ave., Brooklyn (photo dated Feb. 1889)
Silkworth, 795 Manhattan Ave., Brooklyn (photo ca. 1895, subject died in 1901).
Henry W. Biffar, 113&115 4th Street, Cor. South 4th and 4th Sts., Brooklyn (photo ca. 1870)