Today I discovered http://www.nationalgallery.org.uk.
The national gallery’s website offers high resolution scans of art organized by century and decade. Their site allows you to zoom VERY close in to examine fine details of images, so anyone looking for costume resources will do well to check it out. I’m currently geeking out over their 1660s portraits, but I’m looking forward to checking out their earlier collections as well.
I’m pleased to say I’ve discovered pretty much everything I was looking for. The style of dress I’ve been looking to recreate is that of a Baroque-era Paris Hilton. The garments of the woman with resources and time, but not much formality. Less lace, more skin, very little jewelry, and the women are shown either passed out drunk or playing party games. I’ve so far found evidence for bodices being worn to parties without sleeves, bodices being worn with mismatched single-layer skirts, and women going to fashionable social events with either TONS of jewelry or absolutely none at all. Awesome. I can wear what I wear anyway, but now I can feel justified in doing so.