I have also collected WindowBlinds styles over the last 20+ years. I was an avid user of WindowBlinds, and then transitioned to using 3rd party themes for Windows (msstyle mods) and stopped using WindowBlinds for several years. But then I came back to WindowBlinds because it was versatile, and you could use WindowBlinds with several different versions of Windows. When I came back to using WindowBlinds, several styles disappeared from prior years (2000-2015). I also converted several msstyles files into WBA styles from the Windows XP era. Plus, I collected several styles from DeviantArt. Here are a few styles that are hard to find.
ITunes A by Kol
The following theme was modeled after the design of the Pulsar Watch from the 1970s:
Pulsar Metal by Daisuke
Mac OSX Leopard by hblascogm
Flex Texture by i-Umami
Of course, everything Essorant (Retiredmaster) did was very clean...