Quick correction in the code for catalog/admin/includes/classes/order.php
Need to include products_code in the query otherwise the model code does not show on the invoice, packing slip and admin/orders.php

CORRECT

********** In catalog/admin/includes/classes/order.php *****************
Find: around line 80

$orders_products_query = tep_db_query("select orders_products_id, products_name, products_model, products_price, products_tax, products_quantity, final_price from " . TABLE_ORDERS_PRODUCTS . " where orders_id = '" . (int)$order_id . "'");
while ($orders_products = tep_db_fetch_array($orders_products_query)) {
$this->products[$index] = array('qty' => $orders_products['products_quantity'],
'name' => $orders_products['products_name'],
'model' => $orders_products['products_model'],
'tax' => $orders_products['products_tax'],
'price' => $orders_products['products_price'],
'final_price' => $orders_products['final_price']);

Change to

$orders_products_query = tep_db_query("select orders_products_id, products_name, products_model, products_code, products_price, products_tax, products_quantity, final_price from " . TABLE_ORDERS_PRODUCTS . " where orders_id = '" . (int)$order_id . "'");
while ($orders_products = tep_db_fetch_array($orders_products_query)) {
$this->products[$index] = array('qty' => $orders_products['products_quantity'],
'name' => $orders_products['products_name'],
'model' => $orders_products['products_model'],
'code' => $orders_products['products_code'],
'tax' => $orders_products['products_tax'],
'price' => $orders_products['products_price'],
'final_price' => $orders_products['final_price']);


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