Lot of 3 promotional items all ©1976-1979 Jack Mathis Advertising. For follow-up to “Valley Of The Cliffhangers” (see previous item #1714) originally scheduled for release in 1978. This volume did not get published until the 1990s and not in the intended deluxe oversize format but rather as a 2-volume, standard size hardcover set. 8.5x11” photocopy of letter on Jack Mathis Advertising letterhead details the “Preliminary Work Being Done On A New Book With The Working Title Of Republic Confidential.” Exc. 9x12” “Republic Confidential - The True Story Inside The Valley Of The Cliffhangers – Prospectus II” has 16 pages and has numerous bw photos from serials including behind the scenes studio glimpses. Full page color photo of Roy Rogers and 2-page spread showcasing “The Cowgirls” of Republic with several bw photos. Lt. handling wear with pinch creases to spine and slight ripple along right margin. VF. Last item in lot is large 12x17.25” example of how finished book will be presented with multiple bw photos from serials and serial production as well as release chart and information about individual serials. Pinch creases to spine but VF/Exc. Great follow-up material to previous item #1714. First we’ve offered of this material.