Update:
Cold and wet weather prevented me from tackling this problem until yesterday.
Following good support and advice from John I was able to drop the fork enough to investigate a little further.
Cleaned and greased appears to have worked.
Warmer weather will see me completely remove parts and rust proof.
I now understand a little more of how the fork fits the frame. Something new to me.
Always good to learn something new. Keeps the grey matter fresh.
Thanks to all for advice and support.
Really appreciated.
Best
Matt
