Dear Alan,
Many thanks indeed for your further helpful suggestion. We know of Arthur Davidson – indeed Jeremy has played in his son Durrell's scratch (in the old-fashioned sense) orchestra, and enjoyed it. So we may well try and approach to him.
Mercury? I certainly didn't know that Schumann was treated thus. If so, that would seem fairly conclusive, since it's (or rather was) a specific. Where did you discover that?
Let's have lunch (even though the topic may not be all that appetising). I know it's my turn.
yours ever
Eric