I think fantastical flying ships are considered by many to be a key element of Victorian Science fiction, largely I think because they featured so heavily in the Space 1889 game. The very first release in that line was Sky Galleons of Mars, the aerial ship combat boardgame that tied in to the RPG. Lets face it, a large proportion of the aerial gunboat models you see on the net are based on the classic HMS Aphid design, while most people will have never even heard of Robur's "Albatross", arguably the most prominent example of a flying ship from the period fiction.
What's interesting is that looking at the various online VSF gaming forums, such ships are almost universally referred to as Aeronefs, the french word for "aircraft" and popularised by the game of the same name by Wessex Games, but never used in the 1889 line.
Anyway, I'm thinking of going with the classic cliche of zeppelin/dirigibles for the Germans and Cavorite/liftwood based 'nefs for the British. Further down the line, the Russian aeronavy might use rotors for lift (like huge helicopters), the French some Bleriot-type fixed wing aeroplanes and the poor Fenians would have to make do with whatever they could get their hands on.
It's far too late to even consider doing anything for Sunday's game, but the creative juices are flowing. Next week I think I'll have to dig out my old 15mm flyers and see what I can cannibalise for 28mm. I've also got some Zeppelin NT model gasbags that I never got around to using that will be a good starting point for some small scout digs in 28mm.