I cannot help you with the rest of your search, but Barnesville (present-day Ellington) was burned by elements of the 12th Cavalry MSM from their Patterson, Wayne County, base on 22 September 1864.

My sources for this include:
--Broadfoot, "Supplement to the 'O.R.', part 2, vol. 35, 12th Cav MSM, pp. 738-9;
--newspaper article, "Civil War Fortress Discovered in Deer Run," "Reynolds County Courier," Ellington, MO, 8 May 1997.

Bruce Nichols