The super-critical report on the 21, February 1st 1944, was followed, 10th March, by a second, which passed the aircraft for service use. The balancing action of the rudder tab was eliminated, the gearing in the elevator trim was reduced, and a metal elevator (note this, you modellers) with rounded-off horns was fitted. Metal-covered elevators were able to be fitted by units from October 1945.
Apart from that, the back end was standard XIV (unless you want to do a contra-prop 21, which is a different matter entirely.)
If you start off with the PCM XIV, you start with a double advantage; as well as the ready-made fuselage, you have a pair of "proper" XIV radiators (those of the Matchbox kit are a scale 6"(ish) short), BUT this is where the fun now begins (been there, done that, but got it wrong.)
Somehow, I think that Matchbox got Spitfire 22/24 drawings mixed up with those of a Seafire 47, or went to Blackpool to measure a derelict 47 sitting there. Either way, though the wings are usable, the 22/24's root fairings are badly wrong, being a scale 4"-6" (can't remember exactly) too wide at the wing trailing edges. This, when you fit the wing up to the fuselage, gives you a passable fit back as far as the mainspar, but an increasing, triangular gap between wing and root, the further back you get.
I made the mistake of grafting the 22/24's roots onto the Hasegawa fuselage (all we had back then,) when I should have extended the wings' upper surfaces inwards with a triangular piece of plastic.
If Matchbox did use a 47, the too-short radiators are explained by the 47's wider flaps, which didn't drop as far as Spitfire flaps, but still needed truncated radiators, and the too-wide wingroot fairings appear to have been necessary on the Seafires 46 & 47, to spread the angles of the RATO rockets, so that the efflux missed the wider tailplane.
Sorry, I seem to have gone on a bit.
Edgar