It has occurred to me that with a circle cutter in hand and a drill press on its way, I am able to cut lensboards for large format cameras like this outfit. And since I am digging around on eBay for a decent starter lens to fit on a 4×5 camera I picked up a while ago, this might not be a bad thing to learn about.
This page even explains how lenses and shutters are mounted, their constituent parts, et al.