NOTE - I've tried my best to:

1. Make it sound true to the piano.
AND 
2. Sound great on the guitar.

Result = A LOT of odd chords. However, it sounds very accurate. Any corrections 
warmly welcome. Let me know what you guys think. Thanks!

TUNED DOWN A FULL STEP

CHORDS

G (320003@1)    - 320003
D7     - xx0222
D (xx0232@1)    - xx0232
A (x02220@1)    - x02220
A7     - x02020
A7sus4 - x02030
A5     - x02050
Bm     - x24432
Eaug   - x02110

Intro - G  D7 D  G x2

G (320003@1)        D7 (xx0212@1) D (xx0232@1)G (320003@1)    D7 (xx0212@1)       
  Write my name......on a map
G (320003@1)           D7 (xx0212@1)   D (xx0232@1)       A (x02220@1) And ask the ranger where I'm at
G (320003@1)      D7D   G (320003@1)       D7 (xx0212@1) 
  Mark an X......on the spot
G (320003@1)               D7 (xx0212@1)    D (xx0232@1)     A (x02220@1) That place that we both loved a lot
G (320003@1)         D7 (xx0212@1) D (xx0232@1)  G (320003@1)           D7 (xx0212@1) 
  Now turn around......and head for town
G (320003@1)          D7 (xx0212@1)     D (xx0232@1)       A (x02220@1) And hope tonight I might keep warm
G (320003@1)              D7 (xx0212@1) D (xx0232@1) G (320003@1)            D7 (xx0212@1) 
  Well I'll keep warm......this much is true
G (320003@1)              D7 (xx0212@1)    D (xx0232@1)    A (x02220@1) A7 (x02020@1) A7sus4 (002033@1) A5 (x022xx@1) And I'll keep thinking of you too

D (xx0232@1)                        G (320003@1) And somewhere there's a someone
Bm (x24432@1)     A (x02220@1)              G (320003@1)  Who's wondering where I am
D (xx0232@1)                        G (320003@1) And somewhere there's a someone
Bm (x24432@1)   A (x02220@1)         G (320003@1)
  Who tried to understand
D (xx0232@1)                        G (320003@1)
  And somewhere there's a someone
Bm (x24432@1)           A (x02220@1)           G (320003@1)
  Who wants to know if I'm alright
D (xx0232@1)                        G (320003@1)
  But somewhere there's a someone
Bm (x24432@1)   A (x02220@1)            G (320003@1)
  With someone else tonight
Bm (x24432@1)   A (x02220@1)            G (320003@1)
  With someone else tonight

Instrumental - G  D7 D G D7
               G (320003@1)D7D A (x02220@1)Eaugx2 (03211x@1)
G (320003@1)       D7 (xx0212@1) D (xx0232@1) G (320003@1)      D7 (xx0212@1)
  Draw my face......on your map
G (320003@1)            D7 (xx0212@1)   D (xx0232@1)       A (x02220@1) And ask your ranger where I'm at
G (320003@1)       D7D  G (320003@1)       D7 (xx0212@1)  Mark an X......by the stream
G (320003@1)            D7 (xx0212@1)    D (xx0232@1)      A (x02220@1) It's roughly where I was last seen
G (320003@1)         D7 (xx0212@1) D (xx0232@1)  G (320003@1)             D7 (xx0212@1)
  Now turn around......'cause now the sun is going down
G (320003@1)          D7 (xx0212@1)    D (xx0232@1)        A (x02220@1) And hope tonight I might keep warm
G (320003@1)              D7 (xx0212@1) D (xx0232@1) G (320003@1)           D7 (xx0212@1)
  Well I'll keep warm......this much is true
G (320003@1)              D7 (xx0212@1)   D (xx0232@1)  A (x02220@1) A7 (x02020@1) A7sus4 (002033@1) A5 (x022xx@1) D7 (xx0212@1) G (320003@1) A (x02220@1) And I'll keep thinking of you too

D (xx0232@1)                        G (320003@1) And somewhere there's a someone
Bm (x24432@1)     A (x02220@1)              G (320003@1)  Who's wondering where I am
D (xx0232@1)                        G (320003@1) And somewhere there's a someone
Bm (x24432@1)   A (x02220@1)         G (320003@1)
  Who tried to understand
D (xx0232@1)                        G (320003@1)
  And somewhere there's a someone
Bm (x24432@1)           A (x02220@1)           G (320003@1)
  Who wants to know if I'm alright
D (xx0232@1)                        G (320003@1)
  But somewhere there's a someone
Bm (x24432@1)   A (x02220@1)            G (320003@1)
  With someone else tonight
Bm (x24432@1)   A (x02220@1)            G (320003@1)
  With someone else tonight
Bm (x24432@1)           A (x02220@1)          G (320003@1) You're with someone else tonight
Bm (x24432@1)     A (x02220@1)          G (320003@1) With someone else tonight