WordPress: Load templates from within a plugin

gistfile1.php

function get_custom_archive_template($template) {
    global $wp_query;
    $object = $wp_query->get_queried_object();
    
	if ( 'gslstaff' == $object->post_type ) {
	    $templates = array();
	
	    if ( $object->post_type )
	        $templates[] = "archive-{$object->post_type}.php";
	    $templates[] = 'archive.php';
	
	    $template = locate_plugin_template($templates);
    }
	
	//return get_query_template( 'archive', $templates );
	return $template;
}
function get_custom_page_template($template) {
    global $wp_query;
	$id = $wp_query->get_queried_object_id();
	$template_slug = $wp_query->get_page_template_slug();
	$pagename = get_query_var('pagename');
	$object = $wp_query->get_queried_object();
	
	if ( ! $pagename && $id ) {
	    // If a static page is set as the front page, $pagename will not be set. Retrieve it from the queried object
	    $post = $wp_query->get_queried_object();
	    $pagename = $post->post_name;
	}
    if ( 'gslstaff' == $object->post_type ) {
	    $templates = array();
	        if ( $template_slug && 0 === validate_file( $template_slug ) )
	            $templates[] = $template_slug;
	        if ( $pagename )
	            $templates[] = "page-$pagename.php";
	        if ( $id )
	            $templates[] = "page-$id.php";
	        $templates[] = 'page.php';
	        
	        $template = locate_plugin_template($templates);
	}

    //return get_query_template( 'page', $templates );
    return $template;
}