Structural method doesn't really seem to have a lot to do with it; those 1950s naval ships were blimps.
The point is that there's a difference - full out rigid airships versus smaller semirigids.
Again, it got better in the 50s. But one way it got better was, there were places they stayed away from! The Midwest being one--but then again, the vast majority of all American airships of all types were made by Goodyear, in or near Akron Ohio.
http://www.airships.net/us-navy-rigid-airships/uss-shenandoah
Posted as it includes information on the Shenandoah's design, which seems to have been exactly the wrong one for conditions more than anything about airships specifically.
Well, if your craft can only go 60-70 knots at most, it's going to take some time to cover any long distance. There had better be kitchens and beds!
Three days or so to cross the Atlantic. I don't think would be unable to carry more people if you were willing to compromise on those instead of it being first class in a luxury-liner compatible sort of way.