In the Manuals & Catalogs portion of VDH, there are a couple of pdf files on Cornelius compressors. This might be a good place to start for general knowledge of the brand.
Also, your near neighbor Reynoldsburg, Ohio is home to one of the branches of Breathing Air Systems, a good source for compressors if you are in the market. I had a Mako/Bauer system from BAS for about 7 years when I did commercial work.
Too DAAM Many double hoses, It's not a hobby, it's an addiction.