Well, I am haunted now by my own passion! And publicly embarrassed too.

I also searched for a photo of the S of FC Gate Guard and the only one I came up with was that posted by Liffy 1M and GeeRam, which is patently a F2. Therefore, I have to concede the issue as the evidence is damning! (In my search I did find a photo of an F2A that appeared to have the 2 x 30s in the ventral tank).
http://www.!!!!!!!!!!!!!!/open.file/0701565/L/ (not skilled enough to cut and paste the photo).
However, I now seriously doubt my own sanity – I walked or drove past the W Drayton S of FC airframe from Apr 82 until Apr 86 and which was (at least initially) in pristine condition and looked as though it has just been refurbished and repainted when I joined LATCC. I recall a square fin as well as the large ventral tank, hence my conviction of its identity as a F2A. The thing that made the airframe interesting to me as an aeroplane buff was the unusual armament fit I described in my initial post. Obviously, I was hallucinating; probably too much Caribbean Coke in my previous tour. So, I’ll check-in at the Funny Farm.……..