Where are people finding deadstock and good silks these days?

Trying to source some nicer apparel fabrics and I'm hitting walls. Wishlist is silk crepe de chine in solid colors (everything I find online is either too thin or feels synthetic), wool crepe for a couple of blazer projects, Tencel twill for pants, good linen in earthy tones, and any deadstock I can get my hands on. Designer deadstock especially is the white whale right now. Etsy is useless for searching this stuff even though I know it's on there. Where are people actually buying? I know a lot of you destash silks and wools on here, just curious if there are other places worth checking. Also if anyone has linen or double gauze they want to move I'm a buyer.