GUILD Mini-Master Slide Viewer Vintage Craftsmen's Guild photographic slide viewer, with original box, made in the USA. Embossed on the back is "Craftsmen's Guild. Pat. No. 2,550,799". Patent was granted in 1951. Craftsmen's Guild, Hollywood, Calif. U.S.A.". HOW IT WORKS: Drop in a slide through the top slot and look through the eyepiece - point it towards a light source for best results (the sun, a light bulb).
