First off, welcome to 480 ownership! They're great little cars and I wish you all the best with yours
Keep us updated, put up some pictures - it's quiet on this section!
Unfortunately parts are somewhat thin on the ground...I can't help you with a light unit but you might get lucky: can I suggest joining the Volvo 480 Club Europe and posting on their forum (
http://www.volvo-480-europe.org/forum/) as well?
Regards
David