I have seen this post for awhile, and I will try to help. First of all, I've never seen a service manual until I just went to a site, where I found some, but right now my Adobe won't show .pdf files, so I will give you the link, in the hope that it helps you figure out this problem:
http://www.stevespages.com/page7b.htm
Go about halfway, and there is a download called "Crossman Factory Service Manual for All Models", and see what that one's all about.
They also have many others, and I'm sure you can find a similar model that will help you enough to reassemble.
Good luck, and thanks for using FixYa.