Adams' was one of the books Carpenter used for his Thesis, though Carp just copied the song texts and skipped any commentary. He might have taken issue with Adams' wish for "some philanthropic poet to provide a more elevating style of composition"!
Thanks again, all. Useful stuff. Next trip to the UK in late June for meetings in Sheffield and then a chance to play with/for the Abram Morris on the one day a year they dance. Don't think I'll make it to Devon or Herga, but you never know...