Many thanks -- I see you have done it for me.
I had just got similar advice elsewhere, I just thought (wrongly) that it could simply be 'undone' in one go.
I was actually going to reverse the changes as you suggest - originally I just lacked the confidence to do it (or realise that was how it had to be done).
Thanks again for the help/reassurance.

I got this WRONG.
Please can you cancel this changeset.
Sorry!