OK I'm all sorted, thanks again guy's for the advice. I must also recognise my arrogance in not changing the cassette originally. I bought a Shimano CS-HG81-10 from my local shop in the end. Very good place, they're very kind in giving advice, even if they've not got the item in stock. It was only £3 more than
Ebay, although I've got to go back, they undercharged me by £10.
The bike changes gear perfectly, as a bonus the new cassettes also lighter! Cheers