The George Washington with Lucy appears to be the son of William Witherspoon DUNGAN: Rev. George Washington b.12/31/1838 Little Beaver Twnshp PA, m.5/10/1867 Jasper IA Lucy E. MERRILL b.5/14/1845,d.1897 d.o Rev. Thomas MERRILL
I have the same info on your George Washington that you outlined. I lost him in Arizona, too. All the DUNGAN derivatives in AZ seem to belong to another line (Lorenzo Dow), so GW must have moved on. Good luck.