Oops!   Missed Brian's post back there...

Again, I ask who or what is 'Folk' in this context?

I'm using Folk to mean The Revival. I think it's not unreasonable to see it as unbroken continuum from the early years of the 20th century to the present day. Socially, culturally, demographically it occupies the same niche which is no closer to the actually 'folk' whom it regards as its principle source, much less those of a similar social caste today. Folk is thus a construct arising from the condition of social class that operates at several removes from the tradition it postulates, much as Kipling did in The Land. IMHO.