If you don't align correctly the robot arm at the police archive puzzle, one of the documents that you might find is none other than the will of Manuel Calavera, the main character in Grim Fandango. I took a screenshot! What a fun reference to one of the greatest adventure games ever. :D

There is not a fixed position on the archive to find this. The documents (that are not Dr. Morales' will or the lab blueprints) are selected at random. Even if you retrieve documents from the same box twice on a row, the game will tell you that you got a different one.