Here is a detailed walkthrough of replacing the pushrod seals on a /5 with pictures: http://www.pbase.com/dqmohan/prtseals
The seals are leaking on my /5 and after reviewing the procedure, I'm tempted to bring it to one of the local airhead shops and let them do it. It may be too many steps for my short attention span to follow correctly.
It looks to me like your list is good. I think the O-rings are for later models.