Had a couple of Group Build ideas a while back which I'll put forward now while Daniel's subject is at hand:
The first would be called 'After the Battle', the subject being aircraft remains, covering everything from aircraft abandoned at airfields or damaged/ written off in the various campaigns, or scrapyard aircraft after the war, to aircraft wrecks as they are today (pacific wrecks, aircraft recovered from the sea, etc).
The other idea is an 'unusual variant' build covering aircraft converted or adapted to a secondary function (emergency night fighters, armed civil aircraft, engine test beds, test weapon carriers, captured aircraft, etc)
What d'ya's reckon?