Here is an Ebay auction for an NOS C5ZZ 16055 A early left front fender inner apron by Ebay member "nevadawater4u" with a Buy-It-Now of $325.00:
Early produced Genuine FoMoCo NOS 1964 1/2 1965 1966 Mustang & Shelby GT350 Left Front Inner Fender Panel
Date code - 3 10 2D
Have been saving this part for many years but never had the right car to use it on. Finally letting this Very Rare, Very Early Manufactured date showing 3/10/1965. Manufactured same time the cars were. Has all the correct markings and drill location dimples. Windshield Washer bag location is not drilled out like all later made NOS pieces. Still has the dimples not holes for that special car that never had the washer option. This probably will be the only chance you ever have for this rare early produced part.
Still has the shipping tag on it with a date of June 7th 1965.
This is the panel that would have the stamped VIN showing so this would make that wrecked or rusted panel on that high dollar car seem like it never happened.