Was going down from the peak on Pok Fu Lam Reservoir Road and right around Jardines Corner (5 mins down from the peak) was a structure that I assume to be a sentry box. It has a small loophole facing the road uphill (forgot to look for any on the other side) and a clear (sealed) doorframe. It looks very similar to the machine gun 'box' on Wong Nai Chung gap, part of the West Brigade HQ complex ( http://gwulo.com/node/32356 ).
Everything tagged: Forward dressing stations
Location of marker is approximate. This building is clearly marked in the GeoInfo Map. Most likely in current 1:10000 & 1:5000 maps too.
Walked by this Forward Dressing Station on 12th February. It would seem it might have been used by squatters after the war. At that time and before the housing developments, the slopes are full of huts and terraces. The terraces are much over grown but still visible if you know where to look.