Hi all,
Ive been intrested in the above , as My child hood was spent living in Johnstone Castle ( well after the camp had gone)  there are some remains left of the guards compond located at the rear of the football park , there is a small lane that leads from Kings road throught the woods to spruce ave right behind were johnstone burgh social club use to be  about 20 yards south of the path are the foundations and some brick work ,
My grandparents who lived in Spruce  confirmed that these remains were the entrace to the Camp  were the guards were located ,
Reading the Infromation on the site I have the following to add

My Grand father (on my mothers side) was a guard in the camp , During his time there  the inmates were " low grade "prisoners( possibly aircrews)  and were not considered dangerouse ,Until  a group of Nazis, (My Grand father said something about a Uboat Crew) that  were brought in and started causing problems  , this resulted in a riot in the camp , the British guards were withdrawn  and the Polish  soldiers were sent into  put an end to the riot , this resulted in at least one Prisoner being Killed and the Nazis  removed .

One rumor that was doing the rounds was that at least one of the Priosners killed in the riot was buired in the castle Orchard (  this is the area at the side and back of the Chapel on tower rd)  whilst exploring  in my youth we did have a look , but never found anything

Thanks Halo, we willl need to get a photograher to visit.