This should be about right. It could be improved by someone who knows the song 
better though (and has the time/no-how)

INTRO:
A5 , D5 , E5 , A5 (repeat A5 few times)

Verse:
A5 , D5 , E5 , A5
He was born on a summer day, 1951
And with the slap of a hand
He had landed as an only son
A5 , F#5 , E5 , A5
His mother and father said "what a lovely boy"
We'll teach him what we learned
Ah yes, just what we learned
We'll dress him up warmly and
We'll send him to school
A5 , D5 , C#5 , D5
It'll teach him how to fight
To be nobody's fool

D5 , G#5 , C#5 , F#5
Oh, oh, what a lonely boy
Oh, what a lonely boy
Oh, what a lonely boy

In the summer of '53 his mother
Brought him a sister
But she told him "we must attend to her needs"
"She's so much younger than you"
Well, he ran down the hall and he cried
Oh, how could his parents have lied
When they said he was an only son
He thought he was the only one

Oh, oh, what a lonely boy
Oh, what a lonely boy
Oh, what a lonely boy

[Instrumental Interlude]

He left home on a winter day, 1969
And he hoped to find all the love
He had lost in that earlier time
Well, his sister grew up
And she married a man
He gave her a son
Ah yes, a lovely son
They dressed him up warmly
They sent him to school
It taught him how to fight
To be nobody's fool

Oh, oh, what a lonely boy
Oh, what a lonely boy
Oh, what a lonely boy