1950's Red Button Stereo Realist 3D viewfinder.

Here's my Red Button Stereo Realist 3D Viewfinder. I believe these were designed and begun production in mid/late 1940's. These were the first 3D viewers that started the craze. I don't have any photo strips. I grew up using the viewmasters with the round wheel film but was never aware of these. I totally dismantled, cleaned and then rebuilt it.