Someone had asked about this earlier but I don't remember who and it has probably been answered, BUT I'm excited and wanted to post! The little circles on the bottom are markers of how much has been removed, I think there's 3 across the bottom.  My machinist friend finally got my E31 finished and he was telling me it was nice and flat, it had been cut before and I could cut it again.  He pointed to those circles and said they were indicators of how much had been r