I also excised some early Einsturzende Neubauten (old industrial music). They have some metal / found object grooves on some of their early recordings, but they still had some synth and drum machine stuff on there. Kraftwerk has this song "Metal on Metal" on Trans-Europe Express. I'm looking for whole songs with that factory sort of banging. Does anyone know some albums like this? I think Ouroboros posted some noise records that might apply. I'll have to dig up the titles.