[cflsystems]

Ok. In include/func/func.order.php in this function

function func_order_data($orderid)

just before

$products = func_query("SELECT.....

add

// added by CFL Systems
if (!empty($active_modules['Manufacturers'])) {
$join .= " LEFT JOIN $sql_tbl[manufacturers] ON $sql_tbl[manufacturers].manufacturerid = $sql_tbl[products].manufacturerid";
$fields .= ", $sql_tbl[manufacturers].manufacturer";
}

Then you can access it in the template as

{$product.manufacturer}