I contacted Shuttle Moving Co. to help move a heavy (300-400 lbs) cast-iron bathtub up a flight of stairs. They typically move pianos, but were willing to accomodate my request.
They showed up, on time, well groomed and well mannered. After a quick few minutes problem solving on how to accomplish the task, all three strapped the tub to a sled and safely pulled it up a narrow staircase on its side. They let me install the clawfoot legs and then manuvered it into its final spot. They also helped me move a relatively heavy bathroom vanity, which was not in the original job detail.
Good people. I highly recommend for any heavy lifting.