Loose Focus Rings Slrmagic Anamorphot

[Caleb]

Hey Everybody,
I wonder if anybody here could offer any help. I have looked but can't seem to find any useful information about this. I have 2 SLR magic anamorphots (1.33x 50 and 40) and both are getting loose focus rings. The 40 is almost completely useless at this point and the 50 one slides a little bit but is still usable. Does anyone know how i could fix these? I see small holes in the rings but can't see any screws or anything in them to tighten. I'm sure there has to be a way to fix this. Never dropped the lenses or anything they just seem to have worn out over time :/ 
Thanks,

Caleb