These are the "ugly sisters":-
25778 983 B747-48E CF6-80C2B1F 1993-06-24 QANTAS VH-OEB LS-DJ HL7416
24836 808 B747-4H6 CF6-80C2B1F 1990-09-27 QANTAS VH-OEC MR-DE N6009F, 9M-MHN
25126 858 B747-4H6 CF6-80C2B1F 1991-06-10 QANTAS VH-OED MS-AJ 9M-MHO
Comparing the serial and line numbers, it looks like 1990 must be the original delivery date. QF only acquired these aircraft relatively recently.
who ran it as N6009F (or was that a delivery rego.)
A Google search throws up so many different aircraft that it must be a delivery rego.