What bothers me about Dylan borrowing these tunes is that he is sometimes not honest about his sources; for example, "Lay Down Your Weary Tune" uses the melody from the very well known "The Water is Wide", a tune Dylan must have known from the Greenwich Village folk scene, but Dylan has to claim that he got the tune from some obscure Scottish folk song that he came across!

18 months later, I know, and I know Joe Offer was joking but he had it in one. "O Waly Waly" is a Scottish variant of "The Water is Wide" so it is quite possible Dylan originally had the tune from that source.