First of all....I note that there is over 3500 views on this thread, hopefully some have gained some knowledge over the process and havnt made the same mistakes I have made! If I have saved at least one person from making similar mistakes as me than this thread is a success (plus it has probably been entertaining
So I have had a few days to think about this, and I have to admit I was ready to move the bus on, however my wife talked me off the ledge and convinced me to take one more stab at getting it running well enough to get it home. At least at home I can pretty much work on it at my leisure. Never underestimate the helpfulness of a supportive wife!
So I have been looking into what would be involved if it is going to be as simple as just replacing the lifter. The more I have researched, the more unlikely it looks that I can get the lifter replaced without pulling the head (which in this bus will really suck due to access). I have a couple of lifters coming and will do what Christopher suggested above and try and fashion a tool and give it a shot. If that doesnt work I will pull the head.
Ideally I will have the head pulled, lifter replaced, engine checked for any other damage, head replaced and motor running all within two days as again, it is hard to justify any longer when as of today I have not been home for a month due to work.
So I will probably be mid-December before I have a chance to get back up there, but the story of this bus continues!