St James may be a very simple reference either a left over from an older song, or simply a doctor's office located on St. James Street, Ave, neighborhood ... if St James was a popular local reference it may have been used to describe the doctor's office in that area. I am not sure any written trace will be left behind.
The story sounds like one based upon reflection of a real event. The singer heard his friend tell the tale in a bar room, the friend tells of his grief, of his love for her ("she'll never find a man sweeter then me"), and of his wish to go out of this life with no debt. All normal human responses, it seem to me, when coping with the loss of a loved one.