Nick,
I have done a little job on your image. Not sure if you or Bish have used curves before so I have attatched a graphic. There is a thread on this in the Digital Darkroom.
The attatched image was done in NX where I also converted to B&W. The snag with the moon in this phase is as you commented the lack of shadow detail. So B&W was used as a way of increasing contrast to try and bring out detail. Now that the moon is starting to wane, over the period 9th to 14th September ( last quarter ) this is the time to catch more detail.
Note to Admin. If this works problem SOLVED
Don