"Sold Out" image not appearing in certain listings

It seems by design that the "Sold Out" icon does not appear in the New Products, Monthly Specials, and Featured Products boxes that appear at the bottom of a product listing (or when your shopping cart is empty - if you choose to show those boxes with an empty shopping cart). The icon does not show in the regular Featured Product list also.

However, in a regular product listing, the "Sold Out" icon does appear.

I would like to have the "Sold Out" icon appear not only in those boxes, but in the regular Featured Products list as well.

I've looked through the new_products.php, specials_index.php, and featured_products.php in \includes\modules\CUSTOM to see what triggers the icon, but I wasn't able to find it. Can anyone point me in the right direction? Would I need to modify the SQL query to return stock status?

Thanks!