Thanks guys for the detail, especially Mark 9263 for the flight number.
There's a hole in the info I copied when working as a volunteer in the airport archive in the 1980s, there's no mention of it in the 1978 or reprint editions of First and Foremost and my logs show nothing at all!
That must count as the only long haul service out of Manchester I totally missed from 1956 to 1986.
Thanks again folks