Confederate Sack Coat info

[DaveGink]

Hi All,
I purchased a cheap, used, "sutlers row quality" CSA sack coat (medium gray wool with 7 brass CSA buttons, no branch of serice trim, stand up collar, inside left pocket) for an event I will be galvanizing at this weekend. It was sort of an emergency buy, very inexpensive, and may be the only time I use it. My unit will be portraying confederate Cavalry assigned to protect artillery. The organizers have provided no guidelines or year for this event, but only vaguely state that this is a battle "somewhere in the fields of Virginia".

That said, I understand that Confederate sacks were not all that common, especially compared to shell jackets (or were they used more than I may think?).

Were those that were worn issued by the CSA or State Governments, or were they home-made, or private purchased items only? Were they an individual choice of coat, or worn by entire units?

Also, are the brass CSA buttons completely wrong? Would replacing the buttons with wood help add at least a little authenticity to this coat? Maybe turning it into a "sent from home" coat?

I've never really focused too much on the uniforms of the Confederate States, So I'd like to learn a little general information here about CSA Sacks and jackets if possible.

Thanks in advance!!
Dave