I remember working up this tune in the house band for an amateur production of "Lark Rise" many years ago. We got quite annoyed by the sheet music the theatre group had paid good money for as it was frequently less than accurate.

In the case of "Harvest Home", one of our more educated number pointed out it was from Henry Purcell's "King Arthur" and we reharmonised it back towards Purcell from the rather limited version in the book.

may be of interest.