Thanks for all the replies. Although it may or may not be HRH, and I believe the pilot has been identified as part of 825 (?), it is still an interesting activity to try and date the photo given the uncertainty of the airframe.
I have another question to ask HRH, about which exocet attack his comments were made about "laying on the floor with missiles flying around and doing a Rubik cube", so maybe I can kill two birds with one stone. The missile reference is continually used by the "other side" as a confirmation of the attack of the 30th, when I think it's more likely to be from the 25th when Invincible fired 6 sea darts what is believed to be a chaff cloud.
Thanks once again. Absolutely fascinating.
Andy