When I ran the 35mm film through the medium format camera the whole width of the film was exposed, not just the band inside the sprocket holes. However, the supplied film holders offered no trivial way of actually scanning the whole negatives.
Yesterday I did an experiment though, I bought two cheap picture frames, took the sheets of glass out of them and placed the negatives between them and then scanned the whole package.
As you can see above, this allowed me to scan the full width, including sprockets. However, it also introduced another problem, Newton rings – an optical phenomenon that makes the scans look like they are covered by a very thin film of oil. Like oil on wet asphalt. Zoom in on the picture and look on the floor near the sprocket holes, there the effect is the most prominent.
There’s a cure for that as well, more expensive special glass, treated to eliminate such distortions. But those experiments will have to wait until next year.