Assumed Datum Convert to Lat/Long

Is there a conversion formula or tool to take a file (paper-based only; no digital) with notes stating "Coordinate System Is In An Assumed Datum" and find the Northing and Easting (or X, Y) points in the real world (Latitude and Longitude). 

Basically, I want to "proof" where that northing/easting or X,Y is (translates into Lat/Long, state plane).

I have uploaded two .pdf files to show you my dilemma. 

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