I have built something similar out of 1/8in. hobby plywood. Next time I'd use 3/16in. My lens is a Kodak 130mm f7.7 with front cell focusing to 6 ft. It came from an old Kodak folder gifted to me that was in really bad shape, broken strut, lots of holes in the bellows. The lens was clean and the shutter worked so I decided to use the lens. I determined the distance from the film plane by attaching it to a bellows with tape. I measured the bellows extension in mm with the lens moved to infinity. I added that value to the flange distance of the camera body and that was the distance to the film plane at infinity. I cut the wood as close as I could, very slightly shallow, and then brought the final assembly to infinity with paper shims behind the lens. I used RC glossy paper in the film holders just to test if I'd got it right. Now a lot of these old 2.5 X 4.5 inch format Kodak folders moved the entire front standard to focus, but some of them had front cell focusing. If looking for one to salvage the lens then check carefully how the focusing works.