Adding custom CSS classes to Visual Editor “Format” menu

I’m trying to add custom CSS classes to the Format drop-down menu of wordpress’ TinyMCE visual editor. I’m using WordPress as a CMS, with some non-CSS-savvy users.

I’ve modified theme_advanced_blockformats in /wp-includes/js/tinymce/themes/advanced/editor_template.js, but non-standard tags either break the menu or don’t do anything.

Another mystery, standard elements added to the menu (for example, hr) do work — it modified the post/page code properly — but they show up in the Format menu as an empty selection.

(I have looked at: ww.wp.xz.cn/support/topic/165934?replies=3 and blog.circlesixdesign.com/2007/01/03/wp-richtext/, which weren’t of much help beyond pointing me in the right direction for the file.)