Thinking the missing brothers might have gone to Iowa too, I went to the WPA record of Iowa burials
http://iowawpagraves.org/
MCCORD J.J. 1822 06 May 1897 Andrew Andrew Jackson Co. I 31st Ia. Inf.
MCCORD J.M. 1845 - Hampton Hampton, Mott Twp. Franklin Co. G 44 IA inf. Civ. War
MCCORD Jacob W. 25 Oct 1851 04 Jun 1931 Woodland Indian Creek Twp. Story
MCCORD James 1807 04 Sep 1876 Pleasant Hill Rawles Twp. Mills
MCCORD James 1836 1922 Riverside Spencer, Riverton Twp Clay
MCCORD James Charles 1880 1928 Collins Nevada Twp. Story
MCCORD Joel H 1868 24 Nov 1934 Riverside Spencer, Riverton Twp Clay
MCCORD John D. 1 July 1834 30 Jan 1873 Riverside Marshalltown Marshall
MCCORD John H. 1918 Highland Guthrie Guthrie hus. Of Margarite; 3 children; Guthrian 24 Nov 1936, Guthrie Ctr & Co.
MCCORD Julia M. 1859 - Hampton Hampton, Mott Twp. Franklin
MCCORDY Jane 37y 9m 0d 27 Feb 1837 Kisor Muscatine, Seventy-Six Twp Muscatine w/o Andrew