There used to be a trademart site set up years ago where daylily folks would do trades. You signed up, listed your wants and haves and then trading would open on a specific day & time, usually a Friday evening I think. That's when everyone signed up would be able to see everyone's lists.
We do have a Plant and Seed Trading forum on NGA. I don't know that it's been used much for daylilies.
If someone wanted to post a trade list of wants and haves to the "Want List" in this forum you could do that and then use tmail for contact. I tend to view posts in the want list as members looking to purchase or trade and if I have something I can offer that someone is looking for I usually do.