"The fact remains that "St. James's Hospital" did appear in some traditional
versions of the song, decades before Lloyd."
I did a fair amount of research on the 'St James's Hospital' reference when I was annotating Tom Lenihan's version for the Clare Library website - can't lay my hand on the research notes but I'm hoping they turn up during my present sorting out of hard drives for archiving
St James's was a charity hospital for lepers, run by nuns, which was demolished to make room for the present St James Palace.
I think it possible that this was what being referred to in the song
Jim Carroll