While I'm not sure what specific optic this is, I think it's an older optic.  (a) All of the new optics we got from Ramin were enscribed with their #.  (b) This optic appears to have a short arrow scribe line (about the length of the guiderod), and then no scribe line (that I could see through the glass dish) on the other side.  The new optics all have a long arrow scribe line, ~1/2 the full width of the optic, and have clear scribe lines on the opposite side.