I picked up a Canonette 28 at the local good will store; light seals were removed, but before ordering a new seal kit from Jon Goodman, I wanted to get the "sticky shutter" repaired. I removed the rear element and noticed that there was foam and foam residue back there. See the attached picture; you can see the lens there. Removing this lens, and "hitting" the shutter with some cleaner (end of bamboo stick) eventually got the shutter working on all manual apertures with a satisfying "clunk". Now to get the light seals, and, then we have another working camera! JohnS.