Issue Accessing Model in Custom Head Block

Question

I'll prefix this by saying I'm a frontend guy, so forgive my general lack of knowledge but I am trying to learn. I'm using an addon called 'Zeon Manufacturer' (CE 1.9.2), basically associates a chosen manufacturer product attribute with further data about the manufacturer.

I'm trying to manipulate the manufacturers detail pages to add Schema/OpenGraph data but having trouble accessing the model within a block I've added to the head.phtml, the only place that data can go. For example:

<meta property="og:description" content="<?php echo $_manufacturer->getDescription(); ?>">

On the page content block itself, view.phtml, the variables I need are accessed as such:

$_manufacturer = $this->getManufacturer();
$example = echo $_manufacturer->getDescription();

I've also been able to access the model on product pages no issue using:

$manufacturerId = $_product->getManufacturer();
$_manufacturer = Mage::getModel('zeon_manufacturer/manufacturer')->load($manufacturerId, "manufacturer");
$example = echo $_manufacturer->getDescription();

However on my custom block, meta.phtml, I can't any method I try to work:

$_manufacturer = $this->getManufacturer();

Or:

$_manufacturer = Mage::getModel('zeon_manufacturer/manufacturer')->load('example', "manufacturer");

I'm sure there's some core PHP concept I'm missing, perhaps the scope where I can access the model or limitations imposed on the head child blocks before the page content is generated?

I'm trying to learn so please forgive any naivity.

Answer 1

Resolved in comments above with help from @Prateek by gaining an understanding of keys used to load data from a collection.

My solution isn't the cleanest method in the world, but it works:

$identifier = Mage::helper('core/url')->getCurrentUrl();
if(substr($identifier, -1) == '/') {
    $identifier = substr($identifier, 0, -1);
}
$identifier = explode('/',$identifier);
$identifier = end($identifier);

$_manufacturer = Mage::getModel('zeon_manufacturer/manufacturer')->load($identifier, "identifier");