1970 Thunderbird Custom Knives mailer/catalog which measures 8-1/2" x 11'. CONTENT: This is an Original mailer from Thunderbird Custom Knives,Blackwell,Oklahoma.There are 8 pages in the original mailing envelope with a Post Date of "Feb.26,1970".Four of the pages are shown.There is also a page describing the Carbon steel blades and the Stainless steel blades offered.A page describing the 8 blade patterns offered corresponding to the 8 knives(No.1-8) pictured with prices.There is also an order form to be filled out with the custom choices of the buyer.There is a letter from "Batson Heat Treating Inc." verifying the Rockwell Hardness of Thunderbird Custom Knives test blades. Excellent condition