Not a frequent poster so excuse typos. It is indeed a T4 variant, recognisable by the 2 DV windows and unglazed nose.
I had the dubious pleaure of sitting scrunched up on the LH bang seat sharing a very cramped cockpit with a series of sadistic QFIs whose common theory was that the aircraft was a single engined one with a spare on the other side!
Seriously though it was a delight to fly solo when there was enough room to savour its superior handling to all the operational variants(except the PR9)
My first flight was 3 Sep 1969 with Dennis Winterbotom at Cottesmore. We climbed up to 10000ft and having closed down one engine, proceeded to fly a sequence of loops rolls and wingovers. The handling was sedate but certainly an eye opener for a new student having just flown the JP and Gnat.
Happy days.
Flapsin