variable endpoints for webservice

Ok, so it might have been working all along, and I just hadn’t flushed the rewrites!

function my_dept_listing_init() {
    //Easy flush
    if (isset($_GET['flush'])) {
        flush_rewrite_rules();
    }

    //endpoint onto which queries are made
    add_rewrite_endpoint( 'individuals', EP_PAGES ); 

    //This filter acts as a controller, inject into content
    add_filter('the_content', 'my_dept_listing_content_ctrl');
}
add_action('init', 'my_dept_listing_init');

function my_dept_listing_content_ctrl($content) {
    global $post;

    $getName = get_query_var('individuals');
    $post->post_title = $getName;
    //Etc
}

Hope this helps someone!