There has been a rather uncanny turn of events in the last hour. I left the shop to pick up the mail, have lunch and do my banking. When I picked up the mail, there was a small priority mail box that contained a customer receiver that was sent to me to be squared.
When I opened the box, I knew I had to square it right away, and I think you will see why....

Here is a picture of the face of the receiver after being squared. You will notice that there is still some anodizing left in one area. The cutter was touching all the way around at this point, so I didn't cut any deeper. The barrel-extension WILL rest perfectly on the face of this receiver. This receiver really was not bad, I only had to take about .002" off to get it squared.

The reason why I wanted to square it right away was because of "who's" receiver it was. Like I said earlier, none of them never need squaring.....