Thanks for the number, robbo - I'll give them a bell, as well as the ones in Glasgow.
AyJay, I just took the radiator off and had no issues with the fan removal. The fan looks really rusty and crappy - but is otherwise okay.
The radiator itself is in very good condition - just a couple of bent vanes near where the leak is, but no obvious damage to the pipes/bars across the rad.
I phoned a local repair shop and they said there is nowhere in the area that does repairs, so it's definitely a send away job (if I don't go for the Chinese option - thanks for the reassuring opinion).
At least it gives me a good opportunity to clean up the mess under the front bodywork and tank!
oh btw, AyJay - did you have to pay duty and VAT on it?
Update:Thanks for the info & tips, guys - after some phoning around, it's off to these guys next week:
http://www.eastendradiatorsglasgow.co.uk/They were recommended by someone here in a post from a few years ago (they do all kinds of bike radiators, including new ones) but strangely enough, the price now is the same as it was then - £45 plus VAT/postage. Totals about £65
Very helpful bunch of guys, och aye!