Searching may be tough. I collected antique quilts for years, and see some patterns coming back as kits that were done in the 1800s. Some of my own quilts were inspired by the old ones. I love designing, but have always hesitated to copyrite. Too many names for the same block, too many variables. Even if a quilter from 1880 had copyrighted a pattern, can elements of that design be copyrighted today?
I'm bookmarking this thread, hoping someone knows.