I'm interested in playtesting...

But is the rulebook available anywhere? can't seem to find it...

We're working on the new draft, so new play testers will (eventually) get a crack at the new iteration. Check lumpley.com for updates as well!

Is it possible to see an older draft in the meanwhile?

I, too, would be interested in giving a playtest a shot - I've got roleplaying houseguests crashing for the next month and was just about to show them Apocalypse World, but a medieval setting would be very much to their liking, and I do love a good playtest.