I would have to say the isometric view is right. Since the square part is 1/2 way out the back and midway in height, I hope some other users here will take a look and offer an opinion, but I think the drawing is right. Move the square part with the hole in it to the correct location using the top and front views, then check the isometric view. Moving parts in an isometric view is very difficult without a reference point to snap to. As an example, placing a cabinet on a wall in isometric view without a point to snap to is a hopeless task.