Fourth and last pic,
Detail of the bottom of the frame, The 3/8" x 3" plate keeps the forks from rotating on the rod, and helps keep them from sliding unintentionally.
The forks where purchased from a local forklift service company, they where "worn out" by their standards, but lots of life left in them for me. They cost $100.00, but probably could have done better if I had shopped around.