With a light all you have to do is focus and turn the screen to square up and move up or down or even sideways to measure. The screen has a grid on it to square up with, its just the measuring with the carrage is the problem. Maybe something off a old lathe or some sort of a dial calipers. I will try and set up something with my small lathe/mill and a laser. Can't wait for the snow to go away, thinking too much inside the house.
If I get one lure right they will all be ok, until I go to another size bait, these are Musky baits. Maybe I am just trying to get it perfect when really not needed that close, but the bigger the lure the closer it has to be to square.
Wayne