My guess is that it is a 706 SQN OFT Flight cab embarked in either ENGADINE or HERMES either late 1982 or early 1983. After this, 706 OFT Flight resumed operating SK Mk5. I concur that the LHS pilot was John Skinner. In late 1982, only 706, 824 and 819 SQNs were operating Sea King Mk2.
I dont think that the photo was during the Falklands War as it was not a 825 A/c.
The other SQN in the War operating the Mk 2 was my flight 824 C Flight in FORT GRANGE and 824 A Flight in OLMEDA (I think). The side numbers of 824 cabs were 350 - 355. There were a number of spare Mk 2 aircraft available either late in the War or early after it as one of our Mk 2 aircraft that ditched in late June after an engine failure was replaced almost immediately. I dont think that any other unit used any of the spares before they went back to the UK.