The Clifton G. Hill in the 42nd Va. was born in Franklin County in 1839 and moved postwar to Montgomery Co., Indiana. He was living there, according to the 1920 Census. I do not know his date of death. In the National Archives, Microfilm Pub. M347, Unfiled Papers and Slips, there is a C.C. Hill, 4th Va. Cav., who was named on a unit clothing receipt roll dated 15 July 64. I can find no other record for him. Looking closely at your tombstone picture, I think the date of birth is 1812, not 1842. If so, then I think the gravestone you are looking at belongs to Clifton G. Hill, born 1812, died 11 Sep. 1881 in Craig Co., according to the Craig County death records. He shows up on the Craig County Census for 1860, age 47, county clerk, living in New Castle village, wife, Amanda V.; 1870, age 57, deputy clerk, living in New Castle, wife, Amanda V., age 47; and 1880, age 67, lawyer, wife, Amanda V., age 56. I cannot find him on the 1900 Census. Was the wife of the man whose gravestone you sent named Amanda? Hope this helps.