Hi cassie,
I no longer have my saves for this game. As this is the final puzzle and goes straight to the end-game cut scene, I'm not even sure if it's possible to use a save game here.

If it is, and someone has one, hopefully they'll let us know.
Have you tried following the directions from MaG's walkthrough? -
Place the cursor at center of the screen. Every split in the rail track is preceded by a skull sign. As soon as the right or left arrow appears, click to make a selection where you want to go.
Take the right, right, right, left and left fork on the rail track.