OK, well I tried about 100 different ways until I did this:
'cvs checkout -r milex -j openacs-4-6 -j openacs-4-6-3 openacs'
and then nothing SEEMED to happen.
But then I did a:
'cvs checkout milex'
...and wonder of wonders - C's in my output file at long last.
Now the long trudge through the conflicts!
I have an idea why this worked - but depressingly no idea whatsoever why all my other attempts failed.
Thank you very much for your help.
Regards
Richard