First of all, copying files that can just be overridden from the Core to Local is not best practise as it can possibly give you more work when upgrading Magento.
I have tested your case and found your solution:
First of all I rewrite it in my own extension:
<models>
<sales>
<rewrite><order_pdf_items_invoice_default>MycompanyName_Myextensionname_Model_Order_Pdf_Items_Invoice_Default</order_pdf_items_invoice_default></rewrite>
</sales>
</models>
Then I override the function you mentioned above:
$options = $this->getItemOptions();
if ($options) {
foreach ($options as $option) {
if ($option['value']) {
if (isset($option['print_value'])) {
$_printValue = $option['print_value'];
} else {
$_printValue = strip_tags($option['value']);
}
$values = explode(', ', $_printValue);
foreach ($values as $value) {
$lines[][] = array(
'text' => Mage::helper('core/string')->str_split(strip_tags($option['label'] . " - " . $value), 40, true, true),
'feed' => 40
);
}
}
}
}
What I have done here is just removed the part where you draw the label and added it to the part where you print the value.
If you have long labels/values and you want to keep it on one line, I would increase the value in str_split.
Go to
System > Configuration > Sales > Tax > Orders, Invoices, Credit Memos Display Settings
Set Display Full Tax Summary
to Yes and save config.
This should add the tax percentage to Magento's PDF Invoice. You can see the difference below.
Best Answer
This generally comes down to the specific implementation of the payment method. However the default payment methods provide this functionality by first defining a toPdf method - like this
Which in this case will reference this template file. Your payment method might not have it's own specified toPdf method in which case you will end up using the default template which will affect all not specified payment methods.
To customise admin templates I would suggest your own admin theme, see here for details. Just copy the relevant file to the your theme and add your information there.
Another avenue to look into is to update the payment method to provide its specific information similar to how the CC method does it