Only oneworld lounges open at that time are the CX Skyview lounge and the SATS lounge (near the BA/QF lounges) which JL pax can use.
Thanks for that Himeno, after reading your post, I found a review on AustBT and - while not the new QF Lounge - I am sure it will be fine for a couple of hours before hopefully getting some shut-eye on the JL 767, which seems to have a similar J config to the refurb QF A330.
On a broader note, I can't emphasise enough the great service and responsiveness that AFF members provide on this forum.
It is extremely valuable and very much appreciated.