Very interesting stuff. My own interest in the topic relates to my 1903 California motorcycle, probably built by the California Motor Co. in San Francisco, just before Consolidated Mfg Co. bought the company to give is an entry into the motorcycle business. My bike has a California head badge, rather than the later Yale California. The origins of the motorcycle are in California.
Anyway, over the years I have collected a few bits and pieces about Yale history - forgive me if you know all this already.
Ezra E. Kirk (E.A. Kirk in another reference, Edward E. Kirk in another!) started in the bicycle business in 1895, first with the Kirk-Young Mfg Co, and later with the Kirk Mfg Co in Toledo. As can be inferred from head badges above, Kirk manufactured Yale bicycle.
Meanwhile, Snell bicycles were being made by The Snell Cycle Fittings Co, also in Toledo.
It seems that both companies somehow avoided being sucked into "the trust" (the American Bicycle Co.) in 1900.
Kirk and Snell merged in late 1902 to form the Kirk-Snell Mfg Co., with Yale and Snell bicycles produced under this banner until October 1903 when the Consolidated Manufacturing Company was incorporated. Consolidated was referred to as "Successors to the Kirk Mfg Co and the Snell Cycle Fittings Co", so it's possible that the "Kirk-Snell Mfg Co" was an informal name for the merging companies used in 1903, pending the capital raising with the formation of the new company in October.
The California motorcycle was acquired at the October 1903 formation of Consolidated, with L.H. Bill of the California Motor Co moving to Toledo which became the new manufacturing base for the "Yale California" motorcycle. I have seen a period advert for the "Snell California", so it's possible a few motorcycles were sold under the Snell banner in 1904.
Hope this fills in a few gaps.
Cheers
Leon