The middle photo is purportedly the view from the top of the stairs looking south......The row of boxes ran east /west that would have had the rifle on the south side of those boxes.... The official tale says that Lee Harrrrrrvey Ossssswald ( Boooooo Hissss) dashed to the stairs from the east side, (Left in the photo) and with his ex-ray vision he spotted the gap in the boxes on the back side of that row of boxes, then with his superman grip he held the nine pound rifle in his left hand , by the butt and jammed it in that gap between the boxes.
But, when taken at face value, the evidence regarding who was on the 6th floor just before, during and after the shooting excludes Oswald as the shooter.
So Oswald didn't dash across the 6th floor.
He did not stash the MC away
He did not dash downstairs to his rendezvous with Baker and Truly
In this scenario, the MC is no longer required as the murder weapon, it is nothing more than a prop to frame Oswald.
Who was probably in the Domino Room while all this was going down.