I personally have never found Side By Side shirts to be particularly exciting. The demo shirt is cool, but it does not move me. There are also a ton of bootlegs out there, and you can never be too sure about what you are getting.
With all that said, I believe you are looking at an original, old school Revelation Records era Side By Side shirt.
There is the different picture on the back versus the new prints, and that ever so telling Stedman tag. This one looks good folks!