I have recently purchased a new to me Speedaire 60 gal 2 stage compressor and am having a tough time finding any info on it. I have been to Grainger and all they can come up with is a parts diagram, and not a very good one at that. My best guess is that the compressor was made in the 70's and the tag with serial number is MIA. I have heard that Campbell Hausfeld made some for the heads for Speedaire, Is this correct? Does anyone know where I can locate more info? BTW model #3Z494