IMHO there are two different props screwed together. The Paragon was the trade name of the American Propeller Company. They were making props for most of the US planes used during the WW1 and after.
You need to look here on both the front and rear halves to see what is stamped in there. Depending on the customer it will just have a part number or may have the engine and airframe model it is used on.
Stacked props like this were not uncommon pre 1920ish as noone had the tech to build four blade wood props early on.