The current recommended method is to copy across all the old plugins into the new, upgraded Moodle.
It would be a whole lot easier if all the non-core plugins were in one place, then you could just copy one directory...
Just a thought
True, but then Moodle would have a totally different architecture.
I understand, Howard 
I realise it's a big ask...
Cheers,
Mark
I realise it's a big ask...
Cheers,
Mark