Stereviews Keystone c.1920-30's lot x 50 "P" series world-wide trades activities(Educational stereoviews of the early 20th century) Issued c. 1920 30's by Keystone View company. Part of their "P" series. Shows all types of interesting activities from around the world. Excellent lot of 50 different early 20th century real photo stereoviews, all cards with descriptions and titles printed on reverse. Fascinating assortment of interesting views, many of these cards not typical or common. All views remain in nice condition and a