Hi, I know you can definitely update the early series ii models to that of the '04 model, not sure about earlier ones.
There's a few 'kits' for sale on flea bay, maybe a mail to the seller might confirm !!
(or, you could always beg, steal or borrow a face lift model, it's was not just the lights that changed, some 750 changes were made - well acording to LR)
Steve.