[Seagoat]

In case anyone else is interested, I found them!

Here's the heirarchy:
assetslib.vpl > cooked > characters > accessories > wearable_items > cloak > sourceimages > fabric

I have no idea why they never turned up in any of the searches I did before, but I'm thrilled to finally be able to get my hands on them.

EDIT: Ok, I guess those files did turn up in past searches, but because the patterns are saved to the alpha channel, I never actually realized that's what they were until I went browsing just now. All I saw was a square graphic filled with cloth texture. *sheepish grin*