Of course, this would all depends wether the arts for all those ships is drawn or not.
I would settle for either the unkown British skyship on p. 7 of the "Introduction" pdf (yes, that one, sandwiched between a
Grenouille and a
Conquerant, which, IMHO, doesn't look like
HML Leviathan at all) or a 1600*1200 version of Wortroll's avatar

.
Barring that, my vote goes to a nice
HML Raven or the jolly good
HML Ebtesham.