Hi: I live in Madison County and am an active member of the Madison County Genealogical & Historical Society.We have published a series of cemetery books that cover the Combs area, and this is what I have found on George W. Johnson.
Yes, there is still a small settlement at Combs...it still has a post office and a little country store.
George and his wife Sarah Jane are both buried in "Bud Patrick Cemetery" which is located 2 miles south of Combs on Mill Creek Road.George and Sarah Jane share a tombstone and the following information appears on it: George W. Johnson 15 January 1852 - 4 January 1929 Sarah Jane Johnson 13 March 1861 - 18 January 1933
Also buried in the Bud Patrick Cemetery are: Mary Elizabeth Johnson Bynum 22 June 1870 - 30 Sept 1936 Russell Johnson 22 May 1881 - 5 April 1935 Curtis Johnson30 December 1902 - 14 December 1918 and possibly, Albert Ray Johnson who died 15 December 1942 ALL OF THESE ARE CHILDREN OF GEORGE W. & SARAH JANE JOHNSON.
The Cemetery book states that Sarah Jane Johnson was the wife of George Washington Johnson.Sarah Jane was the daughter of Andrew Jackson James and Elizabeth Prater James, found in the 1870 Madison County census, Hilburn township, household #79.
As for descendants, I can check and see what I can come up with.Please feel free to e-mail me at firstname.lastname@example.org.