USA Scott 750, 751 First Day Covers - National Parks Souvenir Sheets - 18 different: Scott 750 with Ioor, Rice, Ed Kee, Grimsland, 1st S.E., Beverly Hills, Dyer, Hertelle Stamp Co. (2 diff.) cachets; Scott 751 with Ioor, Ed Kee, 1st Omaha Philatelic Society, Beverly Hills, Dyer, Grimsland cachets. Various sizes and some mixed condition. High Mellone value. (Est $150-200) (Image)