Bi-fold closet door hardware

I have a bi-fold closet door (wooden) and the door has become unhooked and I am struggling to get it back in. I've attached a picture of the pin and the little door guide (not sure the name of this piece). It seems like this door is older, so I can't easily find these parts in hardware stores. I think at the very least I need to replace the door guide thing, as I think it is worn, which is preventing the pin from latching in effectively. Can you take a look and let me know if you are able to determine what parts I should order?