Just so we don't get confused due to terminology. Have seen people describe both parts identified below as the "headlight bucket"
The item below with the red arrow was painted as Charles described - a semi-gloss black on the glossy side, possibly dipped rather than sprayed. This was not attached to the fender of headlight bucket below when the car was painted. If it has body color it is from a respray at some point in the cars life.
The item with the blue arrow was painted body color. back side, towards the fender, was not always well coated with the paint.
It's refreshing to see a drawing with Ford base numbers used to clarify "slang" (and abbreviations sometimes) descriptions.
The item with the red arrow is more commonly referred to as the "headlamp adjusting ring" or (in military description jargon) - "Ring, Headlamp Adjusting".
Just as long as the same language is used (the forum has recently acquired a few more members from overseas so be accurate).
The "bucket" was sprayed with primer (probably at the casting plant site) then sprayed with the required body color at the assembly plants (more than just the three Mustang assembly plants - Ford used virtually the same procedures at all) prior to them being required on the assembly line. The "ring" as previously stated, was probably dipped at its stamping facility then shipped to the assembly plants.
Jim
