A cricket game on the cricket ground
View of the parade ground
More parade ground
Building 10 at the back?
One of the images I did find during my Google search was the following one of the building in picture 3 which was used as the guardhouse in the TV series. In reality though it appears to have been a contractor's building, as can be seen from this rather excellent picture taken during one of the P.L.A open days: https://flic.kr/p/5HMZcs. Note the 1937 date mark above the door.
The coincidence I am talking about was that during a recent Gwulo.com get together, I found out that one of the regular contributors is actually the cousin of Jerome Flynn - who played Corporal Paddy Garvey in the series. I asked him if he had seen much of him when they were over filming in 1992 and he told me that yes, they had gone over to Stanley Fort for one of the scenes involving a cricket game and were used as extras in the crowd. So I guess it must have been this episode. Anyway, it turns out that Jerome Flynn's dad (my friend's uncle), Eric, was a child internee during the war in one of the family internment camps in Shanghai and went on to become an actor. You can see his IMDB entry here.