In addition to these, Sanford McDonald belonged to Company "B" of this regiment. Service files (which can be ordered here) should include rolls for April 1862 which would state that these men were present for duty at the time.

For those like myself that don't know, South Mills is a few miles NW of Elizabeth City NC along the Pasquatank River. The 3rd Georgia Regiment and a few small Confederate units opposed General Reno's advance in that direction in a three-hour fight on April 19, 1862.

Who is Henry Dixon?
I don't see anyone by that name in this regiment, but there are several Henry Dixons enrolled in different Georgia commands.

It doesn't hurt to ask, but --
images of or documents written by the men in your post will be very, very difficult to locate, if they ever existed in the first place. I would start at the Georgia State Archives. You might also do some work and determine where these men and their families lived after the war. Just bear in mind that you're shooting for the moon here.