Thanks. This was really useful.
The only thing I'd add to this is that I'd either put
DJANGO_PROJECT_DIR right into this script and forget about /etc/
sysconfig/celeryd or break even more things out into /etc/sysconfig/
celeryd such as DJANGO_SETTINGS_MODULE more like the debian script.
Overall, this saved me rolling my own from the debian script.
This should probably be added to github under the contrib section.