Quisling, Many thanks for your response, much appreciated. I had toyed with that but could not get a logical explanation. I was on the wrong track.
I have another couple if you fancy a challenge.
Two words C/H or H/C
5,10 letters. Clue is Bill paid, but no go from here.
8,10 letters. Clue is Sellars improvements
Regards
Yorkshirebob