Believe thats a molded hard plastic piece,
bolted to the bottom of the front bumper\cover assembly, covering the bottom of the radiator.
Likely a Ford part# molded into it; would have to remove mine to find that number.
Ford may only sell the front bumper\cover as one assembly.
Could try a junkyard.
Are you talking about the lower black vanity panels attached to the front fascia? Or are you talking about the splash guard located at the bottom of the radiator to deflect water away from the front of the engine?
if your doing off roading you want some coverage under trac, i would highly recommend doing what your talking about. i cut a trans line first few times i went out from branches i went over, i looked at shaping alluminum but did metal mesh from grill inserts and i will post some pics after it warms up here, the under carriage and lines are exposed, really bad after lifting and way cheaper to cover then replace parts.