Have you got an early LCE adaptor. Mine is for a Leica and is a very snug fit on my 20-60 eyepiece, but it is held in place by 3 small white plastic screws.
Now you will find as you get older all your facilities start to go i.e. a bit hamfisted, and I found these 3 screws a little too awkward to get on with.
Bought eagleeye version which is very good, but my LCE version is a better, snugger fit.
So what to do. Well I am reaonably competent at DIY well I can turn a drill on.
Take one LCE adaptor + one 5mm screw and nut, drill out one hole on adaptor to 5.5mm. Put 5mm screw through hole from inside of adaptor just drilled attach nut, carefully apply araldite around hole on outside of adaptor tighten screw to hold nut in place.
Leave 24 hours. Undo screw and screw in from outside place Andy's electrical tape around head of screw to suit.
VOILLA I can use it again.
Hope this is of use to someone.