Hi,
You can edit the view "product show" and add find this code at the beginning of the file
if (empty ($this->element)) {
$app->enqueueMessage(JText::_('PRODUCT_NOT_FOUND');
} else {
And add one line just after, like that:
if (empty ($this->element)) {
$app->enqueueMessage(JText::_('PRODUCT_NOT_FOUND');
} else {
$this->element->product_quantity = -1;
At this moment, the quantity would be a fake "unlimited" so the stock block won't be displayed.
But there is a side effect : the javascript script which alert the user for the stock won't be added in the page.
Regards,