O.S. Timelines, 1936-76
On their company website, the highly-respected O.S. company of Osaka, Japan formerly maintained a very informative pictorial record of the entire history of O.S. model engine production from the beginning way back in 1936. This feature was widely used by collectors interested in Japanese engines to identify O.S. models in their possession.
However, for some unaccountable reason the historical pages on the O.S. website have now been taken down, leaving collectors without a reference for model identification. Fortunately, thanks to someone's foresight it remains available online at a different location. My thanks to reader Bob Allan for pointing this out.
This invaluable reference had its beginnings in 1976, when the company celebrated its 40th year in business by publishing a printed "wall chart" rendition of their historical timeline as it then stood. Although this document only takes the story up to 1976, it is still a most useful reference. For the convenience of any readers interested in these engines, I've attached scans of the four-page document. I hope that some of you find this useful!