My late dad was a M/Sig Winchman who was given a year's unaccompanied posting to Khormaksar, so I've just had a look through his log books for the period.
His first flight there was 1 May 1966 and his last was 4 February 1967, which covers most of the period you're interested in.
Up until mid-July 66 all his flights were on Whirlwind 10s, after that Wessex 2s crept in. There was a mix of both types right through to February 67, but in my dad's case only about a quarter of his flights were in Wessex's.
Obviously I can't say what was there outside the period he was there.
He took a few photos while he was there - I'll have to work out how to upload them!
Hope this is helpful
