You could always post the gun/mount itself here so we can see it.
If it's an RL mount, a front view(as a source picture) is almost as good as a top view, since it will suggest a lot about the shape and appearance of the turret from above. You might have to do some guestimating as well. It was doing so that I did the 105mm M/32 gun mounts for Erikrike(a front view picture of the mount on Navweaps, and some guestimating on the width).