Many of the units captured at Donelson and Is #10 seem to fall into a dark hole for the 2-3 months after their exchange in Sept. 1862. Most were reorganized and reequipped in the Jackson, Ms area, and in early Oct. sent to Holly Springs to reinforce Van Dorn's defeated army after the battle at Corinth.
At this point, some of the recently exchanged units were sent to Port Hudson, while others were absorbed into the army at Holly Springs.
These units were apparently undergoing multiple regimental consolidations and brigade assignments, but there does not appear to be any clear record of these events during Oct-Nov-and early Dec.
Please let me know if you, or any participants on this board uncover any clues about these organizational "puzzles".