The picture is the right keel for the 30, Mark II model. Without the boat in the water it is hard to tell what the actual draft is. On some boats there is always 6-8' of bottom paint sticking out of the water.
The method to accurately measure actual draft is to run a plumb bob from the rail to a point that is perpendicular to the bottom of the keel. Obviously this done with the boat out of the water. After the boat is launched, rigged and loaded, take a ruler and from the mid beam point check the distance to the water. Do the other side and average the two measurements. Subtract this measurement from the one you took on land and voila the actual loaded draft.
The 30-2 never had a deeper keel as a factory option. A deeper keel would have to have a narrower chord width and/or a taller mast for the design to work. Nice boat and a big 30 footer.