Middle pic both have drain hole at the bottom but the screw holes are odd. I have about 5 of them and non make a matching pair. I have 2 with the drain holes on opposite sides when the screws match upvwed said:Going by the markings on the lens (which I can just about make out through the dirt) you've got the whole unit upside down, hence the drain hole appears to you to be on the top in your first photo.
Bottom picture also upside down.
davidoft said:The screw holes are correct, they aren't a mirror image.