3 of them? Ha! And these are not a common machine either.
It's the view in the last photo. I am wanting to see the screw hole in the slot and also the one just to the left of the slot to know if there is something in there. I have asked on another post here because there is supposed to be a screw on that side. (in one of those holes) I have seen photos posted around the net some showing the screw in one spot and some another, so I am wondering how yours looks.
Mine has the back hole empty and the hole in the slot might have a broken off bit stuck in the hole.