I started researching Rockwell after you suggested this. I had to start work so I didn't get very far, but I will pick up where I left off when I have a little down time. Thank you for the suggestion!Early Rockwell ? Maybe?
I looked at it today. It is actually VB0it doesn't look like a south bend, but it has what appears to be VB6, in the beginning of the id... and my SB9 had VB6 stamped on it too. what you are showing is bigger than a 9... but I was struck by the id. Just for info.