Yeah I said I'd make a new post for this, never actually got around to it. I found where to augment level 75 items - it doesn't need to be in sky, you can do it in Valley of Sorrows. It's an adamantoise type mob that is basically the same as Gudanna except he hits like a truck to a PLD tank.
There was 3 of us, we all augmented our items. As usual, crap for everyone except my Macuahuitl +1 which got a Resist Bind +1. At least I'm not planning on selling it again.