I just picked up a Benelli M4 from an auction house in my home town, frankly stole this thing for $900. It is a sweet set up with a Surefire x400, a nice tactical rail and some great furniture on it. Gun is in excellent condition and adorns a USMC logo on the receiver. I am trying to find out if this is a special edition or if the previous owner had this put on the gun? Pics attached, any input would be great... thanks.