The John Edwards Memorial Foundation put out a couple of vinyl albums produced by Arhoolie Records called "Work's Many Voices" (JEMF 110-111). These were compilations or anthologies of commercial recordings made between 1956 and 1983. Notes by Archie Green. They're not folk songs, and mostly not organizing songs, just songs about different kinds of work. I don't know where they might be available nowadays, but they're very enjoyable.