I don't know how to post pictures on this site but you can see the barrel at www.gunbroker.com
by entering auction number 158760248. There are plenty of pictures of it.
The rear sight has no windage or elevation so it appears to me to simply be there to get a quick fix on the front bead. However, you can drift it over for windage if needed. If Tom says it is fast then you can take that to the bank. Based on his assessment of this barrel I am going to start featuring it as I have that much confidence in what he says about fighting shotguns.