Colleagues, this thread has emerged from deep cyberspace and, should anyone read it, let me add a few facts.
I did prefer XM 214 to its brother 215 - the aerodynamics were better i.e.215 was a bit twisted. I always flew the aeros routine with finned missiles as they improved the stability in the vertical plane - very handy when getting a bit low on pulling out of a loop or executing the prohibited 'Derry' turn.
The Paris Air Show required large airshow ID on the fin and, I think, it was the team's idea to display the Union Flag ( not called the Jack as that term only applies when it is flown on a jackstay on a ship. Why did we display a F1A at the PAS? Later, when still on the OCU, I borrowed an F6 for shows in Canada and the USA.
The blue smoke modification was wholly unofficial and my agreement with the Chief who installed it was that I would drop it into the North Sea if there was any trouble. The back end of a standard 250 gall. ventral was blanked off, a fuel pump from a SAR helicopter installed and pipe work clipped along the outside of the fuselage to the bottom engine jet pipe. Elec power was taken from the rear nav light. I think it was a 'display only' fit but if the jet was flown at night, any residual smoke oil would be ejected when taxying out to the dismay of the ground crew. The smoke oil was copied from the Reds who had Gnats at the time - DERV with blue biro ink and very messy. The main problem with it was the reheat temperature vaporised the smoke and not much use in my display. On the run-in, as per the photo, it had some use but at 50 ft or so there was risk to anyone on the ground. Did the baby in the pram suffer any ill-effects? ( see photo passing the GCA hut). I have recently spoken with a local farmer who was a bit worried about his strawberry crop! Risk management wasn't on the agenda in 1968 and we were lucky to escape a claim which would have exposed the smoke mod. to scrutiny
Happy days.