Exclude featured image and custom field from this get_attachment query

The asker refused to post his solution as answer, so I took the liberty to get this question out of our growing Unanswered Questions list …

<?php 
$logo = get_post_meta($post->ID, '_lm_comm_logo', true);
$map  = get_post_meta($post->ID, '_lm_comm_map', true);

$args = array(
    'numberposts'    => -1, 
    'orderby'        => 'menu_order', 
    'order'          => 'ASC', 
    'post_type'      => 'attachment', 
    'post_mime_type' => 'image', 
    'exclude'        =>  array($logo,$map),
    'post_parent'    => $post->ID
); 

if ( $photos = get_posts($args) ) : ?>
    <div class="slides">
        <?php foreach ( $photos as $photo ) : ?>
            <div class="slide">
                <a href="https://wordpress.stackexchange.com/questions/37715/<?php 
                    echo $photo->guid; 
                ?>" class="lightbox" rel="community[<?php 
                    echo $post->ID; 
                ?>]"><?php 
                    echo wp_get_attachment_image($photo->ID, 'thumbnail'); 
                ?></a>
            </div>
        <?php endforeach; ?>
    </div>
<?php
endif;