Viewmasters (1960s?)

The device itself hails from 1939. I do not know the date of the ad. 50s? 60s? Probably no earlier than 60's per deduction from everett@lemmy.ml below.

It seems like the projector version, you would lose the 3D, wouldn't you? Which is the whole point of a Viewmaster, for my money!

I like this ad style too.