The fail operational 737 is certified for OEI autoland and does it beautifully, the fail passive 737 isn't. As far as i know the second autopilot would disconnect on the fail passiv one, but i might be wrong, don't have the manuals here and it's been a while since i last had a sim event on that type. If dual channel autoland works there still would be the issue of the rudder as the fail passive version doesn't have a rudder servo. In that case the pilot would have to take care of it within the autoland limits to prevent autopilot disconnection.
I believe a few tried single channel "autolands" in the simulator and it kinda works, might be an option if dual channel is not available.