Wouldn't you just rotate the whole unit under the needle? I can't imagine why you'd want to move the card but, then, maybe I'm letting my ignorance show!
Yes, but to do that the card would have to be free to move to north.
The needle is painted on the underside of the top glass which can be rotated and locked in place. The card is supposed to swing so the large arrowhead points due north and it doesn't. I have a Vietnam era lensatic that is set up the same way, top glass etched and card moves to north.
