Enhydra 3.1 and Xerces 1.3.1

I have an Enhydra 3.1 application that that is using FOP.  The version
of FOP that I am using is dependent on Xerces-J 1.3.1.  Enhydra 3.1 also
has its own built-in copy Xerces-J, but that version is a customized
version of Xerces-J 1.2.0.  Xerces-J 1.3.1 does not contain any of the
Enhydra specific customizations.

Question 1: How can I work around the Xerces version problem?  I
downloaded sources for Xerces-J 1.2.0 and Xerces-J 1.3.1 and did a
three-way analysis of the changes made in each version.   There were a
significant number of differences between 1.2.0 and 1.3.1 such that it
will be very hard to patch in the Enhydra specific changes?  

Question 2: Xerces seems like a popular package that is used by several
other tools and technologies.  What did the Enhdyra developers choose to
make a customized version of Xerces?   Doing so makes it hard for
developers to mix Enhydra with other 3rd-party tools and technologies
that also use Xerces.

-tom