Lot of five pieces. This is an early version of this kit that was first introduced in 1939 and ran until 1965. This version was issued c. 1940. 8x11" certificate has Detective Comics, Inc. copyright but is w/o 1939 date (there is a version w/1939 copyright date). Folded once as issued w/handling wear w/a few scattered creases. Pinhole at top left w/some scattered margin wear. Fine/VF. Also included is welcoming letter which has not been folded but has some lt. handling wear w/creases and faint .75" spot of moisture staining. Fine. "Superman's Secret Code" stiff paper folder shows lt. wear w/trace of penciling visible on provided lines. Card has slight aging but is o/w Exc. Comes w/original "Supermen Of America" envelope which has usual and typical wear from mailing and penciling below return address. War bonds postal mark. Fine. 1.25" dia. cello "Superman" button also included in this kit. Design is slightly off-center but totally bright and glossy. Exc.