Are you an ephemera enthusiast like me who likes not only reading surface care literature—particularly instruction manuals—but comparing older versions with updates or trying to catch small details? For example, sometimes it's differently-worded text (supposedly to clarify), cleaner or tool upgrades, or photo or illustration changes.
Recently, I was checking out a couple early '60s Electrolux USA Model L booklets (with no copyright years) and noticed that one of the filter bags collars included a zip code and one did not; indicating that the one without was likely printed pre-July 1963 when the U.S. introduced postal zip codes. Other changes included rewording, and updated illustrations showing various uses of the cleaner. Also, the older one contained a more '50s-looking lamp shade and andiron drawing among other re-sketches.
Another detail I noticed was in the Model LX booklet—"Printed by the Condé Nast Press—Greenwich, Conn., U.S.A". No other Electrolux manual that I've noticed bears that line. I've wondered if different printing companies were contracted prior to the Consolidated Foods era; even during a specific time period for different models.
Did any surface care companies back in the day print its own user manuals? What about other countries' manufacturers?
Anyway, for those who are interested, take a look at this February 14, 2016, GREENWICH FREE PRESS portrayal of Condé Nast Press: