As for the pdf file notation...hopefully this helps and gives a better understanding to what is being discussed on the Key Signature (Enharmonic Keys).
The PDF was written in D#...Key signature has "8" Sharps...it's not practical - F#,C#,G#,D#,E#,A#,B#, & again G#. I don't think this would even be the correct thing to do, with that being said...If you look through the piece there are accidentals (naturals) needed all through the piece because it was written in D#.
ex., D#: G Natural (Accidental) - A# - C Nat - D# - C Nat - A# - G Nat and so on....
In Eb Key signature would simply be "3" flats...Bb,Ab, & Eb
ex., Key of Eb: Eb - G - Bb - C - Eb - C - Bb - G and so on.... (No Accidentals)