bunnyhero+a bit late for #StereoscopyDay but my crude viewer works! it’s basically the wheatstone viewer but with a single mirror. right eye looks through the mirror; left eye does not. you have to mirror flip the right image before printing
here’s a video that attempts to demonstrate how this works, sorta. the left eye sees the image on the far side of the box. the right eye sees the other image in the “mirror world” that is in the same virtual position as the left-eye image