Arnold, I'm sorry, but what you want for @part is something completely different than what I intended. Oddly enough, I implemented what I intended :), which was essentially just standalone "part pages" that bear no relationship to the rest of the document. For example, it is completely intentional and desirable that there is no autonumbering. Other people had asked for this approach (not that I remember who any more), and it is how I have seen parts used in traditional (not docbook-based) books. Now I'm sorry I ever spent any time on it.
Anyway, it makes no sense to me to try to shoehorn what you want into that ill-fitting framework. We could conceivably come up with some new part-level command that does what you want, but, well, I am feeling completely overwhelmed by the amount of effort it will take to define this what-seems-a-tiny feature. (Aside: in general, I can't see how you're *ever* going to get the exact output you want, in every detail, through two different markup systems, each with their own crazy limitations. When I want to control my output, which I very often do, I use TeX directly ... screw everything else. Oh well. I know O'Reilly doesn't believe in TeX.) Sorry, k