Edit: SOLD
This was purchased (new) for a project that never happened, so it is a 0-mile factory differential assembly.
It was sent to OS Giken who opened the case, took a bunch of measurements, sent it to Japan, where they took more measurements, and then they decided that they didn't want to make a racing differential for the Camaro SS after all. So, they reassembled it and shipped it back to me.
It's never been installed in a car, here it is, sitting in a box.
It cost me $1,457, asking $500 plus shipping. It is very heavy, so shipping is probably not cheap. I'm in the Austin area and I'm willing to drive at least a little ways to meet someone.