Yes the canon/bell&howell dial is the one that is spring driven. The Demi comes in a few variants. The higher end models are the Demi s and ee17 which both have the same f1.7 lens though their light meters differ. The others are f2.8 and there was one body that allowed interchangeable lenses, but there were only 2 that were made to fit.
I have a demi s. It's a very simplistic hand wound camera, zone focus, but it retains all manual apertures and shutter speeds. They are coupled together only at the extremes of the exposure range depending on the GN you set so not a big deal. Single stroke.
They are not difficult to fix if you take a chance on one through auction. I fixed mine that arrived covered in mold, with a stuck shutter button, and frozen shutter blades. There is a bit of info online for them as the demi's are fairly popular.