[Jon]

Adapting previous code slightly, here's how I would do do it.

In product.php

FIND:

$smarty->assign("product",$product_info);

BEFORE add:

$product_info['cat_order_by'] = func_query_first_cell("select order_by from $sql_tbl[categories] where categoryid = '" . (intval($cat) > 0 ? $cat : intval($product_info['categoryid'])) . "'");

In product.tpl

{if $product.cat_order_by gt 4 and $product.cat_order_by lt 41}
{include file="buttons/sizing_help.tpl"}
{/if}