771
If I have understood the local news correctly 771 are in the process of 'down-sizing' and this was the last chance for them to have a photo-shoot of the whole squadron at full strength.
I believe they went one down when the duty SAR was called out just to add to the misery of saying goodbye.
I wouldn't be surprised if the Squadron is looking after one of the Mk1's that I had the pleasure of flying a little while back, having been reincarnated as a Mk5.
As Crab says, the time to say goodbye is yet to come at the end of the year.
G.