The two main parts are designated as 'A' and 'B.' In summary, a coin is inserted through a slot from above (not shown.) and its edges fit into the recesses marked as 'D.' The operator pushes on the left end of 'A.' The coin pushes on 'B' and moves it forward. This is the slider mechanism for the gumball machine I made. Reverse the location of the indent to make it on the opposite end.
The drawings show the indent step in the wrong place.