Home-made aluminium 110mm x 110mm lens boards for Toyo Field 4x5 camera. Will fit the Toyo Field 45A, the Toyo 158mm to 110mm lens board adapter and the Luland made 158mm to 110mm lens board adapter. 2mm dural front and 3mm plywood back:

I cut the squares on a Proxxon band saw with bimetal blade and then cut the circular hole with a hole saw for wood using some drops of oil on the blade. The hole saw was nominally 32mm, but the hole ended up 33mm. I then used a Dremel grinder and later a coarse sandpaper wrapped around a cone-shaped object to ream the hole up to 34.6mm. The plywood backing I cut out on a hobby laser cutter and glued it in place with epoxy glue. It is part of a light trap, but also serves to center the lens board. Oddly enough, it is 1mm wider than it is tall.
I finished the boards with matte black spay paint and a clear matte varnish on top.