I am related to Charles Eckles (1715-1783) through his first son, William (1740-1822). I understand that you may be related to Charles through his son, Charles (1752-1830). Eckles is the correct spelling. I have several sources of published documentation proving this. Here is some information on your line that may help your search. Message me if you are interested in learning more.
I. Charles Eckles b. 1715, Ulster, Ireland; d. 11 Jun, 1783, Chambersburg, Cumberland, PA, USA.
He had three wives, and a total of at least eleven children, you are linked through his second wife, Mary Gilkinson (b. 1713 Cumberland, PA; d. about 1760, Chambersburg, Cumberland, PA). Charles and Mary Gilkinson had five children, Francis, Charles, Daniel, Andrew, and Deborah.
B. Charles Eckles b. 2 Feb, 1752, Chester, PA, USA; d. 4 Aug, 1830, Westmoreland County, PA.