Thanks for the reply's.
Let me start by saying the top shown in my original pictures is a replacement. The original top is pictured in the attached photo. Please forgive all of my recyclables in the background.
I replaced the original top, which would accept a capco globe, because the upper plate was cracked and the pot metal corners badly pitted. I thought about shims, which appeared to be an option, but decided to use a 6" to 7" adapter and longer screws to hold the capco in place. This did not require modifying the new top and I don't think it looks bad.