Daniel Ford wrote:
Because there is no *current* RULE for Baghdad (the last expired 2007 according to the table), I assume that DST no longer occurs there.
Essentially, yes. The last transition in the listed rules is the transition from DST to standard time in October 2007, and since then Baghdad has been on UT+3h. Whether this amounts to having "no current rule" is debatable, though: it depends on whether you regard the extent of the rule as being the instantaneous transition or the period of time between transitions. In the latter interpretation, the current rule is the one that says save=0 from October 2007. The current part of the Asia/Baghdad zone definition still says that the "Iraq" ruleset applies.
Given that DST no longer applies (if my Rule interpretation is correct) and the standard GMT offset is +3h, why would these (now identical?) zones be named +03 and +04?
This is not two zones, it is and always was one zone. With DST no longer happening, the "+03/+04" has the effect that the zone's short name is always "+03". The "+04" part of the name format just doesn't get used from 2008 onwards. It still needs to be specified, though, because that zone definition line applies from 1982 onwards, and so also covers times that (per the "Iraq" ruleset) did have DST.
At this stage I haven't continued on my search for a quad-change locality
Africa/Casablanca. -zefram