Kubrick's final three films -- The Shining, Full Metal Jacket and Eyes Wide Shut -- are presented on DVD in the original camera aspect ratio of 1.33:1. They can be masked to create their theatrical aspect ratios.
FMJ is easiest. Go to the shot where the troop is marching along with Gomer Pyle sucking his thumb behind them. The troop is uniform in size, so use the bottoms of their boots and the tops of their rifles as a guide -- give a drop of breathing room. That should approximate a 1.85:1 ratio. The compositions are exquisite. This film was made before digital anything. It's all analog. Tight as a nun.
The Shining was intended for a 1.66:1 ratio. I find a good place to reference is the interview scene, using Ullman's mid-shots at the desk. It's slightly wider than FMJ. But the camera movements take on a greater velocity in cropped form as oposed to the full frame.
EWS is the trickiest. Again, it should be cropped to 1.66:1. However, you need to crop more of the bottom than the top. A good reference is the shot behind Nicole when Sandor Szavost approaches her. Use the top of her head as a reference, then bring the bottom close to the edge of the table, though with a drop of room.
Enjoy.