I play it in C/Am:

Am    C    Am       C      Am
Here's forty shillings on the drum
    C         Am   F       G
For those who volunteer to come
    C       Am       C   G
And 'list to fight the foe today
Am       C         F    G
Over the hills and far away

Chorus

C       Am       C       Am
O'er the hills and o'er the main
   C         Am   F       G
To Flanders, Portugal and Spain
    C         Am       C   G
King George commands and we obey
Am       C         F    G
Over the hills and far away

Et cetera, und so weiter.