P1121 prototype was over 50% completed when funding was dropped by HSA in 1958, expected flight was 1960, and late flights would've been with modifications to the wing.
This was the strike-fighter type, Gyron turbojet (NOT THE JUNIOR), and what seems at best space in the nose for an AI.23 of between 18 to 21 inches diamter in the dish.
Limited to 150gal drop tanks.
Performance would be competative for the era and into the 1970's, with ceiling around 58,000ft (zoom climbs well above), mach 2 speed on the level, but performance was rather lower than the superlative F155T machines.
Wing area is 510sqft same for below.
This type was offered with potential developments for a new J-band radar and Fairey SARH AAM.
But late proposals circa 1960 had a modified two seater cockpit and 28inch dish in a remodelled nose and a recesse in the belly for a Red Bead weapon. Wing was blown (though of the same design as the earlier modified type, but strengthend for 300gal on drop tanks on the inner pylons and 200gal drop tanks on the outer pylons.
Engine would be the Olympus Ol.21R.
Radius of Action over 600nm low level.
This the last P1121 proposal marked the end of HSA's efforts to sell the type to the RAF.