[Vic Piano]

I would agree with you, I thought that Columbia only cast the housing that contained the overdrive. I Googled Columbia Axle Co. and found a bunch of info, but could not find anything from the actual Columbia Axle Co. that confirmed that they did the casting. I talked with John Connelly of Columbia two speed Parts, Inc. and he said that Columbia cast the axle housings for the conversion. It's obvious that the Columbia castings are not as nice (smooth) at the FoMoCo axles castings. There is a brass tag on the Columbia that I have with the following info stamped into it. 40-100A-52 No: 8070 Columbia Axle Co.
Apparently the 40 is the year of production and (according to John Connelly) they most likely were installed in late '39 Zephyrs (like cars, they were produced early). If someone ordered a new Zephyr, with a Columbia in '39, the factory installed the unit. Only Lincoln did this, if someone wanted a Columbia in a Ford or Mercury, the dealer did the installation. I'm going to continue my search and see if I can locate some original documentation from Columbia.