Oh bummer. That's a different story.
I haven't looked that closely at mine, but is the notch near the top of the picture where the case halves meet supposed to be there? It almost looks like a hole that might be created if someone were to pry the case halves apart using a flat bladed screwdriver. Kinda the same question re: the chip near the center of your picture where the casting has a cylinder shaped area for a bolt.
These imperfections may be irrelevant depending on the sealing mechanism when the 2 case halves are joined. It's possible that a "mist" of oil could escape these imperfections and cause the leakage. It may be possible to stop the leakage with a little JB Weld. Make sure you clean the area with a solvent--acetone if you've got it, otherwise alcohol would work--and then be very careful not to put so much JB Weld that it would drip down inside the case. It might even be worth letting the JB Weld tack up just a bit before applying it so it wouldn't be so runny. You may even need to apply the JB Weld in stages--building towards the center of the hole from the perimeter like a welder would fill a hole in metal.
This is a little bit of a hack repair, but it'd be a much bigger job to take everything apart and possibly replace the case.
Of course I'm still very new to the NT700 world so I'm sure there's someone out there in forum-land who has much better and more detailed knowledge of what's going on in this pic. For now, I'm doing my part to keep this thread at the top of the "new" section!