Thank you Becky. It is Bill Grogan's goat and the tune is there too! For those interested, the missing words are:

The whistle blew,
The train drew nigh
This poor old goat
Was doomed to die,

He gave 3 groans
Of awful pain
Coughed up the shirts
And flagged the train.

I see the DT version doesn't have the 'went to heaven without a head' bit. Was that added by the street kids, I wonder - one of those songs that give you a chance to say a forbidden word like HELL-o.
Now, I think I need to go teach that song to some of the kids over here!
Robyn