Replacing a picture in a mono viewmaster toy

Disney had this line of single pictures viewmasters back in the day   My girlfriend is a huge fan of Lion King and I  wanted to replace the picture inside with one of us.  I was curious if anyone else had attempted a similar project and could offer advice.  Thanks in advance

Burf6 years ago
The first thing you must have is a picture that is a positive transparency, not a flat opaque picture or a negative. The old 35mm slides are positive transparencies and will work fine. You will need is a light source from behind and a magnifying lens set at the correct focal length in front to enlarge the image. You can can mount the works in a tube, a box or whatever fits your needs to complete the viewer.