Jabberwok - thanks, exactly my understanding and apparently those of others. To take it one step further, the point put to me was that if a flight plan has been filed, then unless rejected by any of the relevant units then the flight has been accepted as without ADF and is legal and permitted. I still worry if this interpretation is too wide but it would see to follow from the section you quote.
I am lead to believe that discussions may already have taken place with the CAA about exempting aircraft with specific avionics fit - is anyway able to comment.