I read this thread some time back but didn't think I had anything to add...but I was looking at what I've always thought was my 'commercial' P08, particularly at the big relief area between the frame ears (which has no purpose), and I noticed that the cutter mark was odd...It looks like whoever ran the mill ran the cutter into the frame at the end of the cut...but the mark doesn't look like an end-cutting end mill...
(And although the receiver has the C/N, the frame serial is 6782/n)...