1940's Field Stereo Map Viewer

This piece caught my eye because it has a strong lines, strange look, and was optical. The legs look spider-like and menacing plus you have to stick your head over it to look. Piece was designed to give a dynamic field view of military maps. There are two mirrors on the side (one missing but easily replaceable) that give the effect. Legs fold in the piece and has two carrying handles on the top. Quite rare and larger than most viewers of this type. Measures: 24" from leg to leg and 9" H