I did say looks LIKE a KC-141, 4 donks and refuelling sting slung on the back. And yes, naked eyes, very iffy ones sometimes too, still looked something like a 1000 ft or so.
Must have spent a couple of hours over the northern suburbs and south over Palmerston. Maybe 1000 ft is a bit low but it wasn't too much higher and at low speed but not a dirty run, gear was up while I watched it.
Missed the B-52 later. It would explain the presence.
Don't think the RSAF use something that big for their F-16, mostly seen a tanker conversion C-130 with them previously.