First off, as hard as I'ved tried, I can not find any post with Mike Carmony describing his 'hammer bob" prosses, or pictures.
Next I have to ask what does it take to drill through one of these hammers? I thought they were only surfaced hardened.
My drills are not cheep. I knew right away it was a no go
The picture below is what I'm shooting for. I thought I would drill out the places I wanted to remove and then use the Dremel with stones to finish with.... Not looking good for me at this point.