This might help but will need a bit of hacking to work outside our
environment:
http://www.mems-exchange.org/software/files/tmp/zodb_referers.py
Anton and I have found it very useful when trying to track down
references. To use:
$ ./zodb_referers.py -c index.pkl
That will create the index and then start prompting for OIDs. To reuse
the index:
$ ./zodb_referers.py index.pkl
HTH,
Neil