You may have discovered what happened to the rim-set Compur with one of my 13.5/4.5 Tessar lenses in it -- right before someone previous to me removed all the actual shutter parts and left it as a barrel with aperture.
Fortunately, my Speed Graphic has a fully functional focal plane shutter, but that doesn't help you with your Patent Etui.
Do be sure to preserve all shims from the mounting of the shutter to the front standard; you should, in theory, be able to mount the lens you have into any shutter the same size/type and install it with the same shims in the same places, and get your infinity focus to match. I can tell you from experience that this may not be the case with another lens of the "same" focal length; I tried to replace the 13.5/4.5 Radionar I had with a 13.5/4.5 Xenar in the same shutter and found I couldn't focus to infinity -- and the infinity stops on that camera aren't readily adjustable.