For anyone who is looking for correct Lucas fog lights, with the small round o-rings and round-eye covers, for their GT/CS there is a set on eBay.

I don't know anything about these particular lights or the seller.

http://cgi.ebay.com/ebaymotors/68-69-70-MUSTANG-SHELBY-GT500-LUCAS-FOG-LAMPS-LIGHTS_W0QQcmdZViewItemQQcategoryZ140736QQihZ017QQ itemZ270112891636QQrdZ1