So I'm working on a 603 clone, and I've secured a complete upper. It appears to be an older one with a C MP C-marked barrel with a forged/flashing milled off FSB. The barrel markings and FSB would date it at around 1969. The upper is a Colt with no forging codes and the VP and "C" inside a square in front of the ejection port area. But for the life of me, I can't tell if it is a square or round-forged upper. I've been comparing it to the best pictures on the web, and I just can't tell the difference. In some light angles, it looks square. In others, it almost looks round. Does anyone have any really good pictures of both for comparison?