Although not what you were looking for, one of the two guns is currently at Petersburg NB. As to them getting them, they probably went to war with an Arkansas unit, but were turned in as the battery got better guns, probably sent to the Atlanta Arsenal, and then given to one of the GA batteries. Of note, since they were cadet six pounders they would have had a long recoil and so not as desirable as even regular six pounders.

Lee