While looking at compressor pix I came across the Makita MAC 2400, which looks very similar to the 42321 except for a more elaborate instrument panel. Get a parts-list/diagram at DirectTools.com or Google it. I haven't tried any parts, and they're expensive, but it may be worth a try if you're desperate. The 42321 may be a knockoff or it may be made in the same Chinese factory. Who knows?