Here are the instruction books online:
http://www.youcanshopsecure.com/baaice.html
As for that back lever, it looks similar to the 100. It curves toward the rear and fits through a cutout in the body right behind the trigger. Put the trigger on, put the lever in, then use the trigger to hold it in place until the spring tube is screwed in. Once there is some spring tension on it it tends to stay in place.