hi i remember the song well but where I come from (Fife Scotland) we had a chorus too . Fife had many coal mines and I guess thats where the chorus comes from it goes      

Coal for Dysart Dysart coal
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If there's a connection with the Grand old Duke I cant see it   
but thats the way we sang it and very melodic it was to
Sorry you cant hear The melody as it was different from the Verse