I sure would like to know if any of the seasoned large format hole drillers out there ever drilled your own lens board holes, in my case it would be a wood 6" r ounded corners deardorf board drilled for a copal 3 size. My questions would be 1- is copal 3 a 39mm hole or not? 2- What is your home brewed recipe for puttin g that Big hole right in the middle , thanks Dan