There are no more GW inks, they were replaced with washes quite a few years ago. I lament their passing now that I've expended most of my supply.
That being said I use Smoke occasionaly and the GW black wash might not match to well with VMC smoke, you might be able to come closer using a combination of Delvan Mud(brown wash) or Ogryn Flesh(flesh wash) with a bit of Ashurman Blue and black wash mixed in to get that unique smoke color. Another option would be artist inks, chestnut or dark brown ink mixed with a bit of blue and black should give the same basic color.
If you're looking for corroded copper patina, I've used the VMC Verdigris a few times and once you get a handle on how to use it it has that green you see on well weathered copper/brass.