Andrew,
I may not have needed to do it, but one attribute was varchar and needed to be text. I also added a few not null attributes. I thought by the time I figured that out, for several tables, I could write the save/restore script. Then a few days later I made more changes and only spent a few minutes on the save/restore.
I think this also points to the fact that developing with real data can make you realize shortcomings pretty quickly.