Question Author
Thank you all for your answers. I think SUMS is wrong in light of your replies, wyedyed and porilo. It's certainly a clue that is open to more than one interpretation. That's the beauty (and frustration) of cryptics, I guess.
Apologies for "shouting" wyedyed, my handwriting is appalling sp it's very difficult to get out of the habit of penning everything in upper case!