I'm planning to fabricate something similar to Tim's idea for my 2X3 Century. I use Horseman rollfilm backs exclusively with my Century, so in place of the heavier, cast metal, spring-loaded ground glass that came with the camera, I'm looking to take a film-pack back, remove the hinged cover, grind down the depth of the case a bit and mount a ground-glass + fresnel lens inside (at the correct focusing plane of course). The thin metal casing of these film-pack backs are very lightweight, providing a way to shave some ounces off the weight of these cameras. I don't need a protector for the ground glass as my padded camera case provides that function. The pop-out shade that attaches to the original spring ground-glass back isn't much use for me as I employ a traditional dark cloth for focusing.
I've modified my Century so that the front standard tilts forward to allow greater depth of field with all of my lenses (65mm, 105mm, 165mm & 240mm), a mini view camera if you will. With a few filters, lens hoods and a miniscule Metered Light spot meter and the whole package fits in Lowe case not much bigger than a 6-pack of Coke.
So, re-purpose those film-pack backs.