Longreach - I believe Longreach is the generic name given to all QF 747-400's, just as SIA called their first 747-300's "Big Top ". and their -400's Mega Top. QF delivered their first - 400 non-stop LHR - SYD which is a long reach.
( Sorry if the memory has made a few errors - happy to be corrected
I have always understood that Longreach is the QF generic name, however....
The original marketing name was "Stretched Upper Deck"
Fortunately, very late in the day, this was abandoned.
Fortunately - because someone pointed out that it was a very very very bad idea and they should check out the abreviation SUD in medical terms.
Longreach was later adopted and all the
PR speak followed.