Did they keep a record of the data 'as staked', and the 'as built' information?
If yes, this would be your lucky day.
Take that stake out data, and import those points into C3D (or LDT) and connect the points so to speak to create breaklines, and build a surface from that data. Your Point labels will show up at the correct elevations. Also it will create your 3d faces (tin faces) so that you can shade or render those stairs.