Hi Reeks,
Nundle certainly is a nice location, the Hanging Rock area is also a spot worth visiting; make sure you have a current State Forest Fossicking Permit if you are working in the forest proper. Years ago I had just purchased my GPX5000 and found my first little nuggie after a couple of days detecting as a total newbie at HR.
The Hunter Valley express way has shortened the trip by about 45 minutes X Newcastle area, which makes the drive to Nundle a bit more relaxed, will make it up there again for sure. Nice finds such as those you found make for interesting detecting poking around in the forest country.
Cheers, SinHof.