I don't know if this is what you are refering to, but Bill Cohenour's book (do I dare mention that guide?) lists two different versions with the G mm. One has a "low G" and the other has a "middle G". Howdy's guide has pictures of the two variations. In one, the G is near the brass rim, in the other, the G is at midpoint between the ".999 fine silver" and the rim. The three 7's seem to be slightly smaller with the "middle G". The same variations exist for the Running 7 design. The third guide I have doesn't distinguish between the two. Oh, just checked the club web site and the two variations are shown at the link below.