I can see the 9 5/8".
I cant say for sure that I had the ring fully seated when I took that measurement. I do think there is some fuzz on that number even if it was fully seated as the thickness of the tire at the bead should play into it. I seriously doubt that I got my rings bottomed out...
You are making the right choice. Dont rush it, do it right the first time and you will actually be able to enjoy it. Its a solid platform and there are a lot of good parts there but it needs some love to un-sketch it.