Well, I finally got to Camden today (I was waiting until I was sure that M·A·C Viva Glam VI was out).
I toured the entire Stables market and found the stand where Velvet Illusions was last known to be trading from (stand 38-39). No sign of them. The staff at the store that is now there had no idea whether they are still trading let alone where they might have gone too.
I think you're out of luck, sorry! There are still plenty of stores in the Camden markets to get 60 clothing though so it may still be worth a trip if you've never been.