sheesh.. My ruler have lines for .010
Surfster, 1st of all I use a duplicator, but even when I make templates for it I just try and get them close. I can't speak for everyone but I think you'll drive yourself nuts trying to make them exact. Having some variance is one of the things I like about making my own plugs (most of the time... sometimes it drives me nuts!) As long as it swims right and catches fish then it's close enough for me.
As for being hoe'd... post a pic and maybe one of us will show you how much it hurts
-DAve