The rest of the numbers on the mount are smaller like is typically seen. I just showed those pics to show the knob better.Mongo, not sure what to tell you on yours, numbering totally different on mine. Mine are very deeply struck, European style and appear to be machine struck not hand stamps.
That's just how it came from IO, I'll clean it up before I mount it. Too many projects...Mongo, are you aging the "repro" mount? Or did you just leave it out in the rain? ha ha!