There's a lot of minis that Forge World has put out over the years. Some haven't had rules for a bit, but they do no, as Games Workshop has put out rules for what they're calling the Legends kits. They've also added a FAQ for Space Marines and Necrons.
From the article:
Download Warhammer Legends rules for classic Forge World kits, and get the latest FAQs for Codex: Space Marines and Codex: Necrons, and an update for the Black Templars.