Ambrotype of John Cawthorn

In a previous post about John W. Cawthorn (found here) I posted an "enhanced version" of an ambrotype picturing John in his Confederate uniform. At first I couldn't figure out whether this old picture I have which is still housed in its original case was an ambrotype or daguerreotype. Luckily I found a website called Tips... for Dating Old Photo's... and boy was it helpful. I now know that what is in my possession is an ambrotype because the picture needs a dark background to show the photo in positive form.

Here is the original photo I scanned into the computer:

This picture shows the frame, and faded condition of the photo.

Here is my "enhanced version", which in reality may or may not really be that enhanced: