Thank you all for your considerable help and advice and I have now finally come to the end of my problem and it has been staring me in the face all the time.
I might have mentioned that I have two hives and one nuc and I have been stuck in a train of thought that I must combine the nuc with the queenless hive. I was sitting on the summerhouse step this afternoon, pondering on how I can do the combine when it suddenly, you know like a spade in the face, came to me -- why do I have to do it with the nuc?!!!
I have a pefectly good hive, with a queen, not three feet from the failing colony and with identical footprint. Combination should take less than ten minutes to complete. Take the top off hive 2, place QE and newspaper on top of frames, lift hive 1 and place on top -- I don't even need to take the top off hive 1. Go and have a beer.
Doh!
As far as the nuc is concerned, as soon as the hive combination is satifactorily complete I have a spare brood box, job done.
I like to think I am an intelligent man but really, sometimes I wonder.
track
One last thing. The reason the nuc box is in the tight mess it's in is because two weeks ago it weighed nothing and had virtually no stores. I've probably fed about 8kgs of sugar syrup in the intervening time but obviously they have got a bit of a step on and filled it up themselves too.