ooh, a nice black right feed sterling. hmm. this is tempting. I always wished my cf stp was a right feed.
in my estimation it is an older stp. Some of the stp's had that valve body with the matching bottomline kit. My stp has the hose out the back of the valve body, but it is from the last generation right before spyder threaded ones came out.
if we had a picture of the left side and it had a wire detente that would all but confirm stp.