Transactional Emails - Default Styling and Variables in Magento 1.9

I'm looking for 2 specific variables.

Wishlist - The var_message variable has some styling to it that im trying to edit.

Abandoned Carts - pulls on this extension URL : connector/email/basket/code/secret/quote_id/*****

And im unable to find the location of the file that is accessed by that URL or command.

Any assistance that can be provided would be greatly appreciated.

Also if someone could tell me how i might trace the locations of these things without "Just knowing" that would be grand too.

Kind Regards,

the correct variable name is message (not var_message)

variable message is populated in controller Mage_Wishlist_IndexController inside method sendAction

here it is:

        $emailModel = Mage::getModel('core/email_template');

        $sharingCode = $wishlist->getSharingCode();
        foreach ($emails as $email) {
            $emailModel->sendTransactional(
                Mage::getStoreConfig('wishlist/email/email_template'),
                Mage::getStoreConfig('wishlist/email/email_identity'),
                $email,
                null,
                array(
                    'customer'       => $customer,
                    'salable'        => $wishlist->isSalable() ? 'yes' : '',
                    'items'          => $wishlistBlock,
                    'addAllLink'     => Mage::getUrl('*/shared/allcart', array('code' => $sharingCode)),
                    'viewOnSiteLink' => Mage::getUrl('*/shared/index', array('code' => $sharingCode)),
                    'message'        => $message
                )
            );
        }

        $wishlist->setShared(1);
        $wishlist->save();

and the actual content of the message comes from a form input and gets fetched over here:

$message = nl2br(htmlspecialchars((string) $this->getRequest()->getPost('message')));

there is no actual styling or css assigned to it. In fact most of styles are defined inline in email templates