[Dan in Pasadena]

Here is the rear view mirror. I hardly had to do anything to get it this clean as it was in great shape just sitting on the old man's workbench. Rest in Peace Sir, whoever you were. At least a few of your treasures are very appreciated by another man.

The mirror says, "Made in the U.S.A." and "Glare Proof" on the back and on the tilt/night vision tab it says "Glare Proof" and "Guide". I THINK "Guide" is the company name based on the info in the link above.
You can't really see it, but the shape is very square and when the mirror itself is tilted you see a space between the mirror and the frame unlike modern ones. These two things makes me feel it is 60's (or possibly 70's) vintage. I'm thinking this may have been an aftermarket item from a NAPA or Pep Boys kind of place.