Box joints with a band saw. Wow! I like seeing a photographer building their own gear. If you decide that 9.5 x 26 is the perfect format for some project, all it'll take is a trip to the shop. A lot of camera limitations have dropped away for you.

Maybe we should be promoting more do it yourself gear to get the handy types more interested in our passion. For many the joy of starting with a pile of wood and ending up with a beautiful photo is the ultimate thrill.

Hope you painted the inside of the bellows flat black also. If you didn't you'll get a lot of light bouncing around where you don't want it.