If I took pictures of my variety and error coins through both lenses of my stereoscope - could I view them in 3-D through some type of view master device?
There are many ways of doing stereo including using a stereo microscope which will work well for small parts of coins but rarely has large enough field to shoot whole coins. When the object does not move, you can shoot two photos moving the camera between the shots to simulate a left and right eye perspective. Accurate alignment is crucial when the movement is made using one camera for sequential stereo! If you wish, you can adjust the amount of offset between the two shots to exagerate or diminish the stereo effect. Resulting photos can be viewed in any number of stereo devices if mounted correctly. I like the old standard (1850's through 1950's) 7" wide cards but there are many formats. The lack of a standard system was always part of the problem that made stereo photography a declining fad. With practice, you can learn to view these cards by forcing your naked eyes to 'wall' so the left sees the left image and the right sees the right. Beginners can help the process by holding a card betwen the halves so as to block each eye's view of the other image. Some users prefer to swap the halves right to left and view by crossing their eyes but I never could learn to do that. This is no place for a full lesson on stereo photography but the answer to your question is that the idea has merit and is worth your trouble learning to do it.
http://www.stereoscopy.com/faq/freeviewing.html They even have a page on how to view the images but I can't say that I see how their instructions help with parallel viewing which is the way I prefer.
