Proper use of wp_get_attachment_image?

Don’t you need to use get_posts( 'post_type=attachment' ) to return the attachment IDs? So, something like:

$args = array( 
     'post_type' => 'attachment', 
     'numberposts' => -1, 
     'post_status' => null, 
     'post_parent' => $post->ID 
);    
$attachments = get_posts( $args );
$myimageid = $attachments[0]->ID;

wp_get_attachment_image( $myimageid, 'full' );

Otherwise, you’re using $post->ID of 1, which isn’t likely to work.