Here is an Ebay auction for an NOS C5ZZ 16054 A right front fender inner apron by Ebay member "partsace" with a Buy-It-Now of $1,100.00:
C5ZZ-16054-A NOS Ford 1964.5 1965 1966 Mustang Rear Inner Fender ORIGINAL UNUSED.
Will ship well packages via the cheapest delivery method. This has been in my possession for 18 years but I haven’t needed it for any of my restorations. Questions, ask. I love talking Mustangs (not Mach-E’s).
C5ZZ-16054-A NOS Ford 1964.5 1965 1966 Mustang Rear Inner Fender ORIGINAL UNUSED | eBay
-Fred-
Again, I will state that Unicorn horns are more common than this NOS battery side inner apron. These have been obsolete from Ford for well over 30 years now.
-Fred-