Just wondering, are there any Bolt holes on the side of the base near the centre of the flywheel ?I believe this is an engine converted to a water pump as was last used.
The cylinder has a water jacket and connection ports which makes me think it was an engine at one time.
If you look at the images of the engine and saw table you will see that there is a very wide pulley on the engine next to the wall. I suspect the long shaft on the compressor is to accommodate two pulleys mounted adjacent to each other. One would be tightly attached to the shaft and the other would be allowed to spin freely. These are often referred to as a loose and a fixed pulley. With the wide pulley on the engine, the belt can be slid sideways so it will engage only one pulley on the compressor. With the belt on the loose pulley the engine can be started without the load of the compressor. After the engine is running the belt can then be shifted to the fixed pulley.Can you please tell me why the none flywheel side of the crank is so long with a key-way? I do not know much about this type of machinery.