Footnotes are great if you like that kind of thing(which I do) but can be a bit overwhelming for the average reader. It's a general interest book, not a Ph.D thesis, after all. Treat the book as "What A L Lloyd thought and knew about the subject at the time" and you'll have loads of fun.
   As regards Les from Chorlton's original question, I dont recall reading another book on English folksong with that depth of background since. Granted Bert may have been been a slight bender of the actuality), he knew his stuff and had a variety of opinions always worth considering. Great stuff. But beware, the man was not averse to revamping traditional lyrics without telling you what he was up to. And clever enough for you not to spot he was doing it (which is a very difficult trick to pull off).