Theme Hook Suggestion for Drupal 5
In Drupal 5 you need to add the suggestion yourself by placing this function in your theme's template.php:

function _phptemplate_variables($hook, $vars = array()) {
  switch ($hook) {
    case 'node':
      $vars['template_files'] = array('node-'. $vars['nid']);
      break;
  }
  return $vars;
}


Once that's done you'll be able to use node-13.tpl.php (note the single dash).

Source: Separate node template for a specific node.