Tecumseh pre WWII cast iron air compressor

I bought this item at a yard sale for $10. I thought it looked cool. We sell at a local flea market and a guy came up to me asking if I knew what I had. He told me that it's a 1920s Tecumseh cast iron air compressor..possibly for an industrial sized refrigerator. It's never been used and still has the caps on it. I have no idea of its true value.

Excellent