I believe the early aero kit was designed by Steve Everit and built in the UK by Rawlsons, its probably a cheap euro part. Got any part numbers on the back of the lamp ? The early OE fog lamps are VW golf, mark 2.
http://www.jerico.demon.co.uk/rawlson/industri.htm
There's a guy in the club who brought the original moulds, after they closed down the operation
JH :
Met the guy a couple of weeks ago at Goodwood who had the very first aero RT kit fitted to his car. He sold it on shortly afterwards, but the 2nd owner owner has had it all the time since, spotted it at Lemans in 2002, it was again there this year as well