Matelo
I think that fits the bill very nicely , now I think back it had made a heading change just as i saw it and the track looks exactly right -sort of slightly South of west, I knew it wasnt going via Southampton because so much LHR outbounds on SAMPTON departures pass over that area and it was much too far south for the Compton /Brecon tracks for most Europe NA stuff.
So many thanks, been nice to see it sooner with all those blisters and bumps as it seems they are elusive birds very much from the spooky side of the military