Estate sale purchase in San Diego, CA., has “BPM-1000 Forged-Brass” factory engraved inside the hub.  3/4" opening.  AI indicated this is used on runabouts like old Chris-Crafts etc.  Wood is in nice shape with moderate staining, chromed brass shows some corrosion and wear.  As pictured.  Additional measurements in pictures. Starting the auction very low, good luck.