I apologize for butting in to your post, Mark.
If your soldier was indeed with the 1st Arkansas Mounted Rifles, you may find him here;
http://www.couchgenweb.com/civilwar/1stmtrdx.htm
or you can just go to the couchgenweb.com site and enter his name in the appropriate box. When you find him you can apply for his records at the top of this page. Thank you for your patience.