Many thanks for all your replies, particularly NemesisUK, and I have submitted an enquiry to Amayama.com and am hoping they can help...
Just out of interest, does anyone know if left hand drive headlamps can be legally adjusted to dip in the correct direction so as to comply with the UK MOT?
I understand they cannot as it is to do with the moulding of the lens but worth a question as they are brand new.
I need replacement headlamps as they were damaged by an argument with a wall!
The other company I have contacted about this is Nippon Auto Spares Ltd, nipponautospares.com, who are going to see if they can access them from Japan.
Thanks again and much appreciated.