Wow, cool. Love those ship plans.
Okay, NW, a suggestion?
Start us off in Liverpool or Southampton, NOT London.
London was never a major port city, because of being way inland on the Thames. I know we are talking airships rather than surface ships, but without WWII, there would be no airfields across the south of England, and thus there would be no Heathrow Airport, no Gatwick, no Luton and no Stansted.
Port facilities would simply have migrated upwards from surface vessels to airborne vessels. In fact, it would be quite likely that airships would touch down in the sea first and then dock with the regular ship docks...
I draw your attention to the first trans-Atlantic passenger flights, which were made by flying boats (the same as a sea-plane but the other way on... A boat with wings rather than a plane with floats) from Southampton to New York...?