A full list of old nuclear bunker posts is freely available -
https://en.wikipedia.org/wiki/List_of_Royal_Observer_Corps_/_United_Kingdom_Warning_and_Monitoring_Organisation_Posts_(Q%E2%80%93Z)
Those in Sussex are located at:
ROC Post Robertsbridge TQ74272576
ROC Post Rogate SU80572342...
One word on nuclear war (if you haven't seen it) - 'Threads'
The whole film is here - https://archive.org/details/threads_201712
If there's going to be a nuclear war, I'd like Vladimir Putin to fire the first warhead at me and for it to land on my head please.