One piece of advice for the re-assembly, don't over tighten the screw. The tapered head on this screw is kind of soft and will expand if you over tighten, it then locks into place and can not be removed with out drilling it out. Don't ask me how I know....
Last night, when I made an attempt at this, I removed the screw (21), but the barrel/breach didn't want to come out. I didn't try any persuation, ie rubber mallet or prying. Did some searching and scanning through some dis-assembly videos, but didn't find anything. I put the screw back in. So, the live jam spring is putting pressure on that bushing? So, there must be a pin to drive out to remove the live jam? I don't see it in that diagram, but seems like I saw something there on mine.