Better Method for Multiple Meta Boxes

I’ve sort of done this with using the same function to save the meta on the post screen and also on the quickedit. In your case I think you need to add an or clause to your nonce validation.

if (!wp_verify_nonce($_POST['home_meta_box_nonce'], basename(__FILE__)))   
        return;

as

if (!wp_verify_nonce($_POST['home_meta_box_nonce'], basename(__FILE__)) || !wp_verify_nonce($_POST['home_meta_box_left_nonce'], basename(__FILE__)) )   
       return;

Then you could check if the appropriate meta is posted and update for each box.