See this link: http://elearning.winona.edu/jjs/SW4X5/Originally Posted by isaacc7
It's something like a mini-Hobo. You can make the same with an 8x10 back. (Heck, I must have a dozen 8x10 backs in crummy shape that can be rebuilt.)
My concern would be the 'focus free' part. The link above shows a camera with a focusing mount that has foot/metre scales. Very handy. There are ways around a spend focusing helix, especially if you go wide angle. We can pursue that idea if you like.