Eyepiece lens on M6 problem

["Boreham" <boreham@dial.pipex.com>]

I have had Leica M cameras for 12 years but have not had to worry about
eyepiece correction lenses until recently. I have two M6s (both recent
Solms) and I bought one lens initially to make sure the ludicrous price
(£50) was worth it. The lens was a great improvement and fitted easily and
securely to one of the M6s, but on the other it would not tighten up and
remained loose. My reaction was to return the camera to the dealer from
whom I had bought it second hand to have the threads replaced, especially
as the eyepeice rubber looked as though it had previously been fitted with
an eyepiece. A month later the dealer returned it saying there was nothing
wrong with it and enclosing another eyepiece which fitted perfectly ( for
demo only as it was the wrong correction).
I phoned Leica UK who know about the problem of faulty eyepieces, as does
the dealer from whom I bought the first one. Both are quite happy to change
it and supply me with one for the second body but can't give any guarantees
that they will fit except by trial and error.
Has anyone had any similiar experiences or offer advice ?
Mike Boreham