Vintage 1958 Tru-Vue viewmaster from Tru-Vue Company of Beaverton, Oregon. Black molded plastic with red advance lever. Model #502 which is a non-illuminated Tru-Vu viewer was claimed to allow 30% more light to be gathered because of the larger convexwindows. Their claim was that this resulted in "brighter, sharper pictures". The large "white" inserts in this viewfinder are original, however, they are loose and are not firmly attached to the window openings. They are not cracked or broken. They can fall out easily so they need to be attached to the windows. Originally, it looks as if the inserts fit into slits on bottom and top of windows.
Also comes with three (3) "Mary Poppins" #1, #2, & #3 film cards and one (1) "Aesop's Fables" film card. This item is used. In 1957, these viewfinders cost about $1.98! Checkout the information on the viewmaster company website indicated below.