Yep, the extra cowlings are also handy if you want to display the engine. The fuselage cowlings can be removed (they're 'counter sunk' inside), and the seaprate ones are thinner. The wingtips and other parts are in all the ICM Spit kits - easier than boxing specific parts. In theory you could build any variant of the VII, VII, IX and high-backed XVI, with 'C' or 'E' wing, as the Brownings are there too.
The Squadron used clipped-wing Spits, first with 'C', then 'E' wings, and a mix of both, also with rounded and pointed rudders, short and long intakes, the latter more common once they moved to the Continent, as it included the Vokes dust filter.
Here's a couple of code and serial number combinations, although I don't know the pilot's names, if these kites had regular pilots.
FN-C, PT934.
FN-R, PV210.
I think the work Dan and Merv are doing should have codes/serials for specific pilots for the December '44 operation.