Welcome to FT!
The first thing you're doing wrong is searching on DL.dumb. Sign up for a free FlyingBlue account on airfrance.us and search there. Since AF/KL have stopped serving SEA, you should also consider searching out of places where AF/KL/AZ do fly. (Wikipedia is good for helping you figure that out. Off the top of my head, SFO, LAX, and YVR are good west coast starting points.) If you find classic awards in coach or business, you can book them with DL miles (60K r/t in coach, 100K r/t in business). Being based away from an AF/KL destination is normally a downside, but you have AS as your hometown carrier, so the next step is to go to alaskaair.com and look for super saver (or whatever their cheapest award class is) seats from SEA to the gateway you found flights out of on AF/KL/AZ. (Occasionally you'll find DL seats at low to get you to your gateway, but this is generally considered a minor miracle.) If you only use AS, DL, AF, and KL, you can do search by schedule with multicity on DL.dumb to put your ticket together. Otherwise, call with your flight numbers to book.