Patent #719,641: The original 1903 patent for the Dolceola's action, issued to Leander and David Boyd.

Patent #857,380: The improved action (to reduce noise), issued to Leander only, in 1907.

The action as it appeared in the 1904 Dolceola Instructor, and on some instruments. My instrument (serial # 2582, theoretically made in 1905) does not have the "flat jack spring (8). According to Cohen's research, this was added somewhere between #s  2793 (1905) and 3660 (1906).