MIMF

Here is my guess, but I'm hoping that someone can maybe validate this. The top definitely has a radius to it, I can see the arch at on the edges, but the rest of the top has sunken in. My (less than educated) guess is that these were built on the guitar line rather than the mandolin line. I'm wonder...

Anybody know? What's the most reliable way of measuring top radius? I really appreciate any help on this.

Does anyone know what the standard top radius of a 1940's Kalamazoo Army\Navy mandolin is?
I have one with a sinking top, so I'm taking the back off to rebrace it.