Updating documents in Lucene

Hi all,
The way that Lucene seems to work is that
updates to documents are implemented by the user as a document
addition (of the new version) and subsequent deletion (of the old
version).

My problem is that I'd like to update a number of documents which have
their Store flag set to NO - they're indexed, but not stored. I don't
have the original text content of these documents available anywhere
else - is there any way for me to get this un-stored indexed data from
the old document into the new?

I'm actually using the PyLucene bindings - anyone know if that makes a
difference?

Also posting to comp.lang.java.programmer.

Thanks,
James
.