This is an interesting shot from the "Artist's Studio". The original partial-scale model is juxtaposed with the actual monument in the window. You can see that the original design was much larger and envisioned full-torso statues. This was scrapped after the project took a lot longer than anticipated.

FromtheArtist's StudioatMt.Rushmore.originalpartialscalemodelisjuxtaposedwithactualmonumentinwindow.Youcanseethatdesignwasmuchlargerandenvisionedfulltorsostatues.Thisscrappedafterprojecttookalotlongerthananticipated.