Butterfly- A Storm In Heaven

The following is a basic tab for Butterfly.  It is very difficult to work out, but I have discovered that
The guitar is tuned down to D.  This means the strings are tuned as (from high to low) D, B, G, D, A and D.  
Only the two E strings have to be tuned differently: down 2 steps to D.  
It is worth listening to the acoustic version on No Come Down to hear the acoustic guitar playing in this key.  
Iam also sure the D tuning is used in One Way To Go, also on No Come Down.

Intro : (electric)This is a D chord, it is not entirely correct but is useful as a starting point.

D--------------------------------------------------------------------------------------0---This chord used ----
B--------------------------------------------------------------------------------------3---when 1st electric fades
G--------------------------------------------------------------------------------------2---(It is also used in
D----------0-0---0---this riff ad-libbed throughout intro------------------------------0----the intro to the No 
A----------0-0---0---------------------------------------------------------------------0----Come Down version
E-0-3(bu4)-0-0---0---------------------------------------------------------------------0-----------------------

This is all I could work out, maybe someone else could finish it?

Transcribed by S.H.