I am at about the same stage as you...so I am by no means an expert, but you might try the Vintage Airstream site (airstream.net, I think). I found an excellent diagram of the Dometic and they also give several troubleshooting solutions. When you get there go to the vintage library then go to the 1965 Caravel
owners manual. Its 25 or so pages in. It is a slightly newer system as it has a flint lighter, but the mechanics should still be the same.
Good luck and check out my post on AS comedy club for a laugh regarding this topic.