Each is original glassine envelope w/instructions and cut-out insignias. Kellogg's premium issued w/boxes of Pep cereal. c. 1942. Planes consist of 2.5x6.5" thin balsa sheets w/printed parts. Numbers/plane names include - #1 Supermarine Spitfire V, #2 Bell P-39 Airacobra, #3 The 1-16 B, #4 Republic P-47 Thunderbolt, #5 Curtiss P-40 Tomahawk, #6 Boulton Paul Defiant, #7 Grumman Wildcat, #8 Brewster Buccaneer, #9 Hawker Hurricane, #10 Vickers Armstrong Wellington, #11 Curtiss Commando (C-46), #12 Vultee P-66 Vanguard, #14 Consolidated PBY Catalina, #15 Martin Marauder B-26, #16 North American P-51 Mustang, #17 Curtiss Hawk 75A Fighter, #18 Russian Stormovik. #19 Grumman Avenger TBF-1, #20 Curtiss Hell Diver (SB2C-1) Dive-Bomber and #21 Curtiss Seagull (SO3C-1) Scout-Observation. Missing only #13. Eight envelopes include "For More News About Peps Model War Planes - Listen To The Adventures Of Superman, Monday Through Friday - See Your Newspaper For Time" text on envelope backs (see item #2342). Significant wear to envelopes 9 and 18 which are just Good. Others have scattered wear and even moderate aging. Fine/VF overall. Enclosed balsa airplane sheets are Exc./NM. Nice World War II premium group.