Re: a honest to "Great Maker" barn find upright Maytag
You found a 1/2 HP upright Maytag engine which would have likely come off a model 43 wooden Maytag washing machine. There aren't good records for the dates on early Maytag engines but my best guess would be about late 1917 or 1918.
You don't find these in unbroken original condition very often! Don't strip it down and repaint. It will retain more value if left in original condition.