Greetings,
I think the Turret Azimuth Indicator was standard on, at least, US tanks prior to the introduction of the M1. Was not a compass, just gave degrees with 0 degrees being forward.
Was used to build range cards and for targeting during periods of limited visability (night, fog, snow or in conjunction with a searchlight tank).
In addition, we should be able to have our 'head' sticking out of the turret and use either a TC overide to rotate and lay the main gun or 'talk' to the gunner to lay the gun on a target / orient it with the hull.
Regards,