I's easy to find images about the instrument panel, but finding out the purposes of the "double needle" is harder. Here's another image from the net:
http://members2.clubphoto.com/_cgi-bin/getImage.pl?imgID=486791-ed73&trans=
http://members2.clubphoto.com/_cgi-bin/getImage.pl?imgID=486791-ed73&trans=