If the camera works, I wouldn't discount using a rollfilm back or cutting sheet film. Indeed it sounds like a pain, but 5x7" shooters cut down sheet film all the time, and say that once you get the hang of it, it's not so difficult. You need a rotary trimmer, and the general approach is to put two pieces of tape on the board that you can feel in the dark, one to cut along the long side and one along the short side. If you are confident about your ability to keep the emulsion going the same way at all times you don't need to notch the film, but if you want to notch the sheets, you can use a hole punch in the upper right hand corner of each sheet. A rollfilm back would be even simpler.

You've got a working camera with three lenses and holders, and quarter-plate is a format that hardly anyone uses anymore, so you might find that it has interesting possibilities.