changing page types
1. Edit Page
3. Select your 'Right Sidebar'
You may have to do all 80+ pages individually. This will probably take about 30-40 mins. If you also set the page defaults then at least you won't have to worry about it when adding the same page-type in the future.
Or as Jordanlev mentioned above, you could try Dashboard>> Sitemap>> Page Search>> Select all pages>> click on one of them and select 'Design'... whether this will apply the design to all the pages is something I'm not sure of (Haven't tried it myself).
Maybe someone else has a hard coded solution. I'm sorry I couldn't be of more help.
Now does anyone know why some page types refuse to be deleted...?