I've never done any of the drifts, but have hiked the upper river (Money's pool area) and from gun club off Mackenzie road up to the falls and back. Definitely can go from below the falls to the gun club. Not sure where the pullout is below the gun club. I'd ask at Gone Fishin' in Port A. or Nanaimo for specifics.
If you find the "fishing with rod" website, he has a lot of info about fishing the river