bbc
If you are talking about current RAF Sqns (and exclude the 600 series currently issued to some of the Aux AF sqns) then at least 1 GR4 would be in the formation, 617 Sqn formed 23 Mar 43. And then prior to that I guess a Nimrod MR2 of 120 Sqn 01 Jan 18.
Not sure about the other 2 though.