Shirley Collins recorded this as Nottamun Town on Folk Routes, New Routes which she made with Davy Graham in the early 1960s. This was hailed as innovative then and still sounds so to my ears. I believe she got it the tune from the Ritchie family of Kentucky who had in turn incorporated an originally English text. I'm not sure of Dylan's precise source of the tune he used for Masters of War though would have had ample opportunity to hear Shirley (and her various wannabee imitators) performing Nottamun Town around the London clubs in 1962/3.