I'm afraid daihatsu is the only supplier for the radiator (it is quite a special form). You might find a used one online, but for a new one you have to ring daihatsu...
There must be somewhere in Coventry that can still repair a radiator. Back streets used to be full of them.
Here is a place in Redditch which is not too far away: Motorads Services Haven't used them myself but worth a call.
