Subsequent searching by one of our readers came up with a couple of interesting snippets, courtesy of the Crocker Langley directories;
The San Francisco Call of April 22, 1900 stated;
The Oakland Tribune, Oakland, CA, Friday Evening, September 22, 1905 stated;
The Oakland Tribune, Oakland, CA, Saturday Evening, September 23, 1905 noted;
Warren Mortimer Watson in 1906 is listed as a Royal Arch Mason in the Alcatraz Chapter No. 8a, Oakland, Alameda Co., CA.
And lastly; Warren Mortimer Watson died May 6, 1913, in Alameda Co., CA, at age 67.