Sandy Denny's best recording of this song is the BBC Session version with Bob Harris from Nov 14, 1973. 
It's available on Disc 2 of the re-issue of Sandy Denny's "Like an old-fashioned waltz" (2012) 
Also in the "A boxful of treasures" Sanny Denny box (2004). 
 
Like many jazz standards, it originally had a slow 12 bar intro section, often ignored. 
Sandy dosen't sing it, so it's also omitted here. 
Verse 1
     Bb 
I'd work for you 
    F7M5           Bb 
I'd slave for you 
         Bb/A  Bb/Ab  G9   Dm7  G7 
I'd be a beggar or a knave for you 
    Cm7                      F7         Bb 
If that isn't love, it will have to do 
          Bb�              Cm7   Ebm6   F7 
Until the real thing comes along 
Verse 2
 
     Bb 
I'd gladly move 
    F7M5           Bb 
The earth for you 
             Bb/A    Bb/Ab     G9    Dm7   G7 
To prove my love, dear And its worth for you 
    Cm7                      F7        Bb 
If that isn't love, it will have to do 
            Eb6              Gm6    A7    D 
Until the real thing comes along. 
Middle 8
 
               A�          Em7    A7        D 
With all the words, dear, at my command 
              Ab�    Em7   A9        D 
I just can't make you understand 
            Eb�              Em7       A7        D 
I'll always love you, darling, come what may 
            B� 
My heart is yours 
         F7 Ab� F7 
What more can I say? 
Verse 3
 
     Bb 
I'd sigh for you 
    F7M5        Bb 
I'd cry for you 
              Bb/A  Bb/Ab        G9  Dm7  G7 
I'd tear the stars down from the sky for you 
    Cm7                      F7         Bb 
If that isn't love, it will have to do 
          Eb6                Bb 
Until the real thing comes along. 
Note: Take the Bb at the end of line 2 of the verse as barré on the 6th fret. 
Then just walk the bass notes A - Ab down to the G9 chord. 
(There's no need to play full Bb/A Bb/Ab chords, just do the little walking base line.)