WW1 GB does sound like a good idea.
another idea ive been playing with is the "Disbanded Nations", in witch the idea is to build a model of a vehicle/aircraft/ship operated by a nation that does not exist anymore (for exsample East-Germany, Rhodesia, Yugoslavia, Austro-Hungaria,.....). however, Nazi-Germany would not be allowed.
another idea woulb be a "Next-Generation GB".
where we build models of future vehicles/aircraft/ships (exsample F-22, F-35, LCS, UCAV/UAV,....)