cover 1c-10c Kans.-Nebr. overprints (658-679), complete sets, tied by 'Washington, D.C. May 1, 1929' first day machine slogan pmks. on separate pale yellow covers with typed address, both 1c and 1½c covers have an additional regular issue stamp to make up the proper 2c letter rate, a very fresh and neat matched set of first day covers, no. 660 faulty prior to use, otherwise fine-very fine, Scott retail $1,377.50