Jack Bruce – Theme For An Imaginary Western chords

The chords I could get by ear. Since I needed the chords written and I couldn't find any
score nor tablature for this song, I posted what I could get. NOTE: The "?" is a chord
which I'm sure it's there but I can't figure it which is it. It's the same chord through 
the whole song. Any corrections is welcomed.

INTRO: G Bm Em

         G     Bm         EmWhen the wagons leave the city
         A                  Ffor the forest, and further on
         G    Bm      EmPainted wagons of the morning
       A                    Cdusty roads where they have gone
          G        Bm           EmSometimes travelling through the darkness
        A             Fmet the summer coming home
        G   Bm      EmFallen faces by the wayside
          C        ?         G     BmLooked as if they might have known

      Em         BmO the sun was in their eyes
      Em            Bmand the desert that dries
       C       GIn the country towns
          A        Em      B Cwhere the laughter sounds

      G      Bm       EmO the dancing and the singing
      A               FO the music when they played
      G    Bm         EmO the fires that they started
      A             CO the girls with no regret
      G                BmSometimes they found it
               EmSometimes they kept it
      A              FOften lost it on the way
            G    Bm     EmFought each other to possess it
         C       ?        G   BmSometimes died in sight of day

      Em         BmO the sun was in their eyes
      Em            Bmand the desert that dries
       C       GIn the country towns
          A        Em      B Cwhere the laughter sounds

OUTRO: G Bm Em A F G Bm
Em C ? G