I bought a book on timing, and tuning Contenders and wouldn't reccomend it. There is much Contender info on the inter-net, even exploded diagrams with part numbers.
You have an early model frame not an easy-open, it's easy to tell the difference, even from here. If there is not a cast in cougar scene on the sides of the frame or if it's a very low serial #, you might have a collectible.