After partially disassembling the lens, I was able to free the adapter. No wonder it was wobbly, it was held together with only one of 3 screws. And, I doubt this is original, but there was a o-ring in the sandwich of parts making up the adapter. My guess is that the o-ring was added to compensate for the 2 missing screws, leaving a path for light to enter without it.
The aperture stop spring and bearing was also missing.
xs4me2