I just watched the credits at the end of the Panorama show (which was linked in the original post by GUEST,Brian_M) but found no info on the music credits, but I think I found a slight lead at 4.04 mins. The part in which the song is used is in an old piece of footage with the title The Mining Review with an RCA Sound Recording brand below the title.

This is a page from The National Library of Scotland archives (may all the gods, Celtic and others, bless archivists and librarians including retired ex-librarians like me! Sorry! Couldn't stop myself!):

The Mining Review

That link refers to a specific episode but a search of their film archive may reveal the correct footage and if you are really lucky the credits will give the answer to our mystery. If it is not in the Scottish archive it may be in another one.