My god Ken
I hope you cut and pasted that
I think that what is going to happen is I am going to separate these moodles in to the highest common denominator and do a march with as you have said, hyperjumps in the march
I will then have to set some aside that do not work properly and insert the jumps that I have identified have caused the problems
The maintenance modes issues are the fact that there will need to be intervention in the browser at various stages. I do not need to keep people of the server as the original will go in to maintenance mode, using a maintenance.html file (no CLI on 1.9). However, I understand that this on 1.9 still allows admin users to login.
Once this has been done I take a backup and move to an upgrading staging server, so once there I can take it out of maintenance mode, by deleting the maintenance.html file, as it will be running on a different private URL
I think this will be the process
Cheers