I need help tracing the service history of Mason Hartley of (what would become) Cleveland County, Arkansas.

My 2nd G-Grandfather, John Hartley, was born in 1863 in that area. Family history tells that his father, a Confederate soldier, died in the war and never saw John.
Through 1860 census records and land records, I can document that John's parents were Mason (c1820-?)and Nancy Dixon Hartley (c1830-?) (sometimes spelled "Heartley"), newly relocated from Georgia.

I began to dig through the Gerdes' AR Civil War website for information about Mason. I found a single "Hartley" listing in a place I would expect, the 2nd Arkansas Cavalry Battalion, Company B. This company was raised at Mt. Elba, within a few miles of where I know Mason's son John to have lived. Here's the listing:

Hartley, James T
Private—Enlisted in Co. B, 2nd Arkansas Cavalry Battalion, at Mount Elba, Arkansas, February 22, 1862; transferred to Co. D, 2nd Arkansas Cavalry Regiment, May 15, 1862; promoted third sergeant, May 24, 1862; wounded, date or location not stated; born c1836; veteran filed Arkansas pension application #2387 from Monroe county, July 6, 1896; bought land in Cleveland county in 1860.

I was able to find a grave marker for J.T. Hartley (1837-1899) on the find a grave website (no confederate marker, in Woodruff County) and his wife, Nancy Keath Hartley (1842-1900). I'm confident that J.T. and Mason were different people, and I can document that Mason's wife remarried in 1867.

According to an online database search of Arkansas land records, there's only one record of a Hartley buying land in Cleveland County in the mid-1800's. That listing is for Mason Hartley, who did buy land in Cleveland County in 1860.

Could it be that somehow Mason and J. T.'s service history was confused and combined over time? Where do I go from here? Any help is greatly appreciated.