Following on from my previous comment: would a bulk advance order for this first song book encourage the re-issue of the others mentioned by Joe:
The Penguin Book of Canadian Folk Songs, compiled by Edith Fowke, published 1973
The Penguin Book of American Folk Songs, compiled by Alan Lomax, published 1964
The Penguin Australian Song Book, compiled by J.S. Manifold, published 1964
The Second Penguin Australian Song Book, compiled by Bill Scott, published 1964

i.e. can the possible purchasing power of the 'cat prove to be a motivational force ??

Nigel