What I have is not to your question, but the one person in Arkansas who may have had infomation that you need was Bryan Howerton. However he has passed several years ago an I do not know what happened to his records. He was the primary researcher for Arkansas Regimental historys on line. He spent many hours in the National Archives in Washington DC.
As for my part shortly after we formed the Patrick Cleburne Camp SCV in Pine Bluff we became aware of a marked U.S.C.T. soldiers grave in an abandon cemetery on the property of the 34th Ave. School of the Pine Bluff School District. About 20 of us went to the cemetery, which had a number of graves, and cleaned the entire cemetery. This was in 1986. The grave in question I can not remember the name of the soldier now, but he was a member of the Battery "H" 2nd US Colored Troops Artillery in Pine Bluff. I found that interesting in that they were formed after the 5th Kansas Cavalry was mustered out in 1864, their five 12# mountain guns, used in the Battles of Helena and Pine Bluff, were used the arm that battery.
The sad part of this story is that after we cleaned and restored the cemetery on that school's property. the school took no care of it and eventually destroyed it and all the monuments so that there is no trace of it now.