To me, they're like a cooler version of Retrospeck and Satin Taupe. (Which is my HG combo, actually). Very similar. Retrospeck is just a bit more gold/champagney, and Satin Taupe is more plummy.
That probably isn't a ton of help since Retrospeck is a Lustre, though. Shimma paint might be worth checking out, too. Actually, maybe add Chiaroscuro to that list as well.