Yes it is a good score for 20 big ones well done. Yes you are missing the top cover for the battery bracket. Which is kind of important as it holds the battery in place. With the starter motor strangely theirs not much different to a car starter. You would really have to pull it off and make sure the throw out gear is engaging and spinning freely. Possible may just need some lubbing up. As it could have been sitting for many years. Also check the flywheel make sure it is clean and free from junk. Oh also make sure it has teeth on it as I have seen some with no teeth. Hope this is of some help.
