If you want to use it without altering/harming it, you can always have a new back made to fit it that takes 4x5 film holders. Also depending on how the original bellows are mounted, you MIGHT be able to remove them without destroying them and have a new set made to fit. I'm doing this (on a bigger scale) with a 12x15 Watson "field" camera (I use the term loosely - it's a tailboard model that is effectively self-casing, but it has no carrying handle and it is solid mahogany so it weighs a ton). The original bellows for it were completely shot when I got it so I'm just going to make (or have made) a new set.