The photos show one of the weighbar shaft components.
Below is the old pin and bush, both original items and both badly worn (the large notch in the pin is not supposed to be there! ).
The view above shows the new pin, bush and collar fitted in the end of the rod. This pin connects the rod shown to the weighbar shaft, the other end of the rod is attached to a large spring.
The weighbar shaft is attached to the reverser and lifts and lowers the valve gear to give different positions of forward and reverse. The tensioned spring on this rod assists with lifting the considerable weight of the valve gear into the reverse positions