Quite a nice kit, originally the Airix mould, now with the slightly over-priced additions. The cockpit colours were the standard Cockpit Green (not Interior Green that's the American colour).
You're correct re the cannon barrels.
The seat was still the bakelite red/brown, although by this stage some had been re-painted black, and some in Cockpit Green!
The exterior colours were as stated, the 'Ocean Grey' being the same as Dark Sea Grey (it was re-named, IIRC, in 1947).
Note that 80 Sqn, in Hong Kong, had the blue tip on the white spinner.(Some instructions, including those for the Revell, ex-Matchbox 1/32nd scale kit, show a Sky spinner.) I should have some pics of their crates somewhere.
You'll need to check the style of the serial numbers too, as there were 'square' and 'rounded' types used on the 22/24.
Note that there's a 'triangular' moulding in the approximate position of the flap actuator, on top of the wing. This shouldn't be there.