looks like I should be scanning tonight...
I'll start digging tonight - I can't find the .jpg file of that Zenith/Apex/Universal washer info I had.
While researching the history of Beam-Franklin-WCI a few years ago, I found the obvious early traces of DNA in Speed Queen, Hotpoint, Coronado, Wizard, etc. but those ended rather quickly for most companies once Franklin absorbed much of Beam - though the Beam design carried on in the Speed Queen lineage for many years after. I have some late forties washer service books from Gambles and their Beam machines were branded "Coronado" back then and I have seen no reference to the Marquette brand in any other Gambles literature. Western Auto had the "Wizard" brand, also made by Beam and later Franklin. Do you have anything showing this inter-mixing of brands between Gambles-Coronado or Western-Auto Wizard?
I have a catalog from a builder's supply house in Minneapolis called Janney, Semple, Hill & Co. from 1956 that carries a few brands but their premier offering was Marquette and the machines were Beam - 212 degree agitator arc, porcelain inner and outer tubs and fluid-drive. All Beam just a couple of years after the Apex-made POD.
This Apex agitator design was also made for Zenith, Universal and Montgomery Wards - the Marquette half-sister discovery adds another piece to the branding-puzzle of the 1950's appliance trade. Very cool.
I'll get the scanner going tonight after work.