In 1850 there is a David Truman in Fayette, Pa who is living with Samuel and Mary Truman.Since he is 40 and Samuel is 45 I would imagine he is a brother. In 1860 Samuel has a 6 yr old son named David H.The older David still lives with them. In 1870 the older David disappears and there is a David age 21 who lives with an Amanda Truman and family. he works on a farm and was born in Pa. In 1880 the older David lives with Mary, his sister-in-law and David H lives next door. Those were all I could find. None listed in Pa after 1880.