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.
The scenery ones are cool though! Virtual travel to see far flung places, before the internet. Plus, you got to see it in 3D.