Margret Dean Smith's 'A Guide to English Folk Song Collections', 1954, lists all songs in English folk song collections (and some books that aren't really such) up to 1952, incuding many in the English folk song journals. In 1951 the English Folk Dance and Song Society published "An Index of English Songs contributed to The Journal of the Folk Song Society' and its continuation 'The Journal of the English Folk Dance and Song Society' to 1950". In a few years we can probably expect another volume giving songs collected since 1950 (with journal name now chanced to 'Folk Music Journal'. But there are already a lot of songs. Steve Roud's index keeps expanding and he's now working on obscure American collections, too. He said in a recent note that few Americans as yet have his Index, and he is working on the American folksongs to make it more appealing to them.