Steven, sounds like you understand it, or peeked at the inventor's explanation of it in his first post on the link I posted above
You ought to post your observations on the Practical Machinist site thread.
I think Mr. Newbould's goal was to have something simple and direct reading that didn't require look up tables or a lot of addition or a lot of cranking. He was trying to solve a problem in his production machine shop.
I can see myself coming up with a gear with a non-integer number of teeth (if I were ever to try machining one), but then I'd be wondering why the robot made funny grinding noises and wouldn't run. (I did remove about 60 degrees worth of teeth on my Jeep's pinion gear once, but that wasn't for indexing clearance.
)
Incidentally, folks, if any of you can locate some of the esteemed members of the Practical Machinist forum in your area and get them as a team resource, you'd be doing good. There are some very talented people there. A couple have mentioned FIRST Robotics, and I've plugged it several times.
FYI, Newbould's current product web site:
http://www.newbould.com/Newbould01/index.htm