Vintage ZENITH models L403F,  L403G,  L403R,  L403Y and 4L41 (Ch. 4L41) 4 tube Superheterodyne AM radio receiver.  Original old Sams Photofact manual includes schematic, layout, alignment instructions, voltage & resistance test chart, repair parts list. 4 pages. Dated 1953. This manual would make a sensational accompaniment to your classic radio equipment collection.