Interpretation of jazz piece

[quaver]

I am studying "Saturday Night" by George Thurgood. Grade 8 RCM. I have been classically trained so this piece presents a challenge.  Firstly, there is no key signature which to me could be C major or a minor.  However the last chord is d minor.  Could this be in the dorian mode.

With classical music practicing I strive to perfect the fingering so that I can join notes and or chords and also to reach subsequent notes in an easy transition.  I, however, believe that this being a jazzy piece that technique would not be used so strictly.  I think 'have fun with it' would be more in order than trying to be so strict with fingering.

Could anyone give me hints on how to perceive this piece.  I hope someone will be able to help me as I am new to this kind of music in my piano repertoire and any help towards understanding how to interpret and play this piece would be appreciated.  I thank you very much.

Incidentally I have emailed the composer but did not get a reply.