I have a W.W. Grainger Tomahawk wood chipper that I bought from Troy-Bilt around 1980 in one of their marketing experiments. Troy-Bilt started selling the same model the next year with red paint (mine is green) and the Troy-Bilt name all over it. It is a fantastic machine but now 23 years later, I need parts. Engine parts I can get anywhere, it's the chipper blade and shredder knives that I need and don't really know where to get. Since W.W. Grainger was bought by Troy-Bilt and then Troy-Bilt was aquired by MTD, is MTD my source for parts? The current MTD line shows nothing like what I own, but I know that Troy-Bilt sold similar models to mine for several years. Is any part of Troy-Bilt separate from MTD? Does anyone know if W.W. Grainger still exists? Many thanks for any info you can give me!