The gauges I saw (this was a few years ago) had a definite hump in the center, were made in China and sold through an American chain of suppliers to woodworkers. I checked by placing the long edge of a machinist's rule on the surface, aiming it at the light and looked for gaps. Your methodology is a bit unusual. Any tool sold should be usable, and if these are functional it's a good thing. I still think it's not ethical to copy the work of someone else. I've been the victim of people cashing in on my efforts and I don't want to be a part of that. As I said before, these are ethical decisions we all make every time we buy anything. You may not have the reservations that I do, and that's OK.

Bob Lang
'