It depends on your VIN and which part you are talking about.  308x7S100001
to 308x7S121513 is the total range, where x=3 for coupe, x=6 for
convertible.

For example,
S104047 - end of Nov.
S111833 - end of March

Also, you can check the body build date on the trim tag.  For '63, these are
"week" of the build, not the day.  So A3 is the third week of September, not
Sept. 3rd.  1964 and up us the "day".

Early in reference to the floor storage areas is up to Nov, I believe.  Late
for when Muncies began is around Feb, I think (could be wrong).  Late for
when AM-FM began is around March.

Late for the gas lid is a broad timeline. The switch began May around 15,000
but some July cars had the early style lid (Noland's survey is incomplete
and wrong at 18,000 for an end).  However, most cars by 17,000 - 18,000 did
have the late style.  If you have a '63 lid on yours, keep it or replace
with the same style.  The styles are roller or nylon slide.  The roller is
considered "early" and the slide is considered "late".  The roller uses a
nylon wheel on a spring clip with an exposed hinge and the slide uses a
nylon plunger with a covered hinge.

Trim Parts does some of the nicest repro parts in the way of tail lights and
such.  Might be true on the lid also.