It's strange Singerdave, it appears that several online sources of the song have been removed from circulation, and access is forbidden.
This is silly, as the 'black faces' refer to coal miners after they come home from the pit. Do you suppose the title makes people think it's a racist song???
My grandfather and all my uncles (Geordies) worked down the pit, and all naturally had black faces when they arrived home, and huddled round the coal fire. My granny washed my grandpa's back while he sat in his tin bath!