Apparently from what i can tell, the original Williams 1 was also made in a special Swiss Champion edition. Now interestingly it was identical to a normal Willaims except it had an improved sound system and different decals on the paintwork. Even more interestingly they too were numbered 001 to 500. So it may be that 0001 is not in fact unique as the only 0001, although it is still unique as it was the first manufactured.