Vintage NATIONAL model NC-2-40DR and NC-2-40DT 6 band Superheterodyne radio receiver.  Original old Sams Photofact manual includes schematics, layouts, alignment, adjustments, voltage & resistance charts, parts list. 10 pages.  Dated 1948.  National Company Inc.  of Malden, MA.  This manual would make a sensational accompaniment to your vintage audio equipment.