I found a site that has all the LA City Directories listed and searchable. Found some interesting stuff in them there pages..........I included the first 2 paragraphs from my prior research because well, I think there's a new "origins story" forming.
A 1907 listing of "Tool Makers" in Chicago lists an A. Plomb at 77-83 W. Lake.
In 1910, voter registration records from Los Angeles, CA show Alphonse Plomb as a "Tool Manufacturer" at 1658 Long Beach Ave. Subsequent voter registration records from 1936 and 1944 show he and his son Henry J. Plomb listed as Tool Makers.
In the 1910 LA City Directory, Alphonse Plomb is listed as a tool maker located at 1658 Long Beach Ave. In 1913 and 1914, he is listed under Tool Manufacturers and located at 7674 1/2 Male Ave.
The first time Plomb Tool is listed as a company in the LA City Directories is 1916. In this directory, Jacob Weninger is listed separately as a tool maker, William Ziegler Jr. is listed as manager, and Alphonse Plomb is not in the directory. Charles H. Williams doesn't show up associated with Plomb Tool until 1917. He appears to be Secretary for Eucalyptus Hardware Association prior to 1917.
In the Los Angeles City Directory for 1909, Jacob Weninger is listed as a Wire Worker. In 1913, he is listed as a tool maker. In 1916, he is listed as a tool maker, but separate from Plomb. In 1917 he is listed with Plomb Tool Mfg. Co. In 1918, he is listed as Foreman. By 1920, he is simply listed as a tool maker. In 1923, he is listed as Foreman of Plomb. In 1925, 1926, and 1928 he is still Foreman. In 1934, Weninger is listed as Superintendent at Plomb. On Jacob Weninger's 1942 Draft Registration, he is listed as a tool maker for California Tool Co.