A Vietnam Era Helicopter tail rotor

Description

This item was sold to me as a Vietnam Era helicopter tail rotor.  I have tried to verify this with online sources and have not been able to find anything.  I personally know nothing about this sort of item.  It measures 47.5 inches long and is 10 inches at its widest points.  It is one solid piece of aluminum and weighs about 20 pounds.  If anyone can enlighten me about this, I would welcome your input.  Thank you for checking in.
It is assumed that this item is for display purposes only and not to be used on an aircraft.  All liability for doing so is assumed by the buyer.