Re commutation due, see:
"Commutation For Rations
While going over the compiled service records of Pvt. Hugh C. Queen of Company C, 1st Georgia Regulars, I came across an interesting form. It was a commutation for rations signed by Hugh's company commander for Hugh to be reimbursed for rations consumed while he was on furlough.
According to the form, Hugh was on furlough from 16 July 1863 to 11 August 1863. It was calculated that Hugh was reimbursed for 26 days at 33 cents for a grand total of $8.58.
The record shows that Hugh received his reimbursement at Apalachicola Arsenal, Florida on 12 September 1863."
http://www.authentic-campaigner.com/forum/showthread.php?17526-Commutation-For-Rations