Trac to Bugzilla Migration?

Any tips, scripts, or other artifacts that will import data from a Trac instance to a Bugzilla instance work less?

We have a modified Bugzilla, so importxml.cgi will most likely not be a good choice. Even if it was available, the problem becomes "how to map Trac data to Bugzilla data".

As complicated as it is, I think we will need to do a database to database migration with some mapping tables on the side. Ugh.

Any help is appreciated!