Who are those three hoodlums standing by the truck with you?
Yes I guess the word original is a polite way of saying it’s really ugly.
In the movie at about 7:45 you can see a little winch on the ground under the carriage. Small cables from the winch run through a series of pulleys make the carriage go back and forth. The winch is powered by hydraulics from the saw mill motor and I control it from a little lever up by the Mack steering wheel.
There is no play in the wheels and the rails (6x6 inch angle iron) , they fit very well.