This acoustic version can be found on a CD entitled "I Found My
Tulip" containing other acoustic versions of their songs and some interviews

This pattern is repeated throughout the entire song.
   Cm                              Eb/B
e|-----------------------------------------------------------------|
B|-4-----4-------4-------4---------4-----4-------4-------4---------|
G|---5-------5-------5-------5-------3-------3-------3-------3-----|
D|-----5-------5-------5-------5-------5-------5-------5-------5---|
A|-3-------3-------3-------3---------------------------------------|
E|---------------------------------6-------6-------6-------6-------|
   Fm                              Ab
e|-1-----1-------1-------1-----------------------------------------|
B|---1-------1-------1-------1-------------------------------------|
G|-----1-------1-------1-------1---5-----5-------5-------5---------|
D|-3-------3-------3-------3---------6-------6-------6-------6-----|
A|-------------------------------------6-------6-------6-------6---|
E|---------------------------------4-------4-------4-------4-------|


UPDATE:

When Kevin Barnes plays this, he actually uses a guitar that is tuned down 
a whole step, that is, two half-steps. Then the song is in Dm(relative to tuning):

   Dm                              F/C
d|-1-----1-------1-------1---------1-----1-------1-------1---------|
A|---3-------3-------3------3--------1-------1-------1-------1-----|
F|-----2-------2-------2------2--------2-------2-------2-------2---|
C|-0-------0-------0------0-----------(3)-----(3)-----(3)-----(3)--|
G|---------------------------------3-------3-------3-------3-------|
D|-----------------------------------------------------------------|
   Gm                              Bb
e|-3-----3-------3-------3-----------------------------------------|
B|---3-------3-------3-------3-----3-----3-------3-------3---------|
G|-----3-------3-------3-------3-----3-------3-------3-------3-----|
D|-5--(5)--5--(5)--5--(5)--5-----------3-------3-------3-------3---|
A|(5)-----(5)-----(5)-----(5)------1-------1-------1-------1-------|
E|-----------------------------------------------------------------|

Obviously this pattern has variations over the length of the song, and the
notes that are sometimes substituted are written in brackets.