I believe that you can recover the Pages ’09 v4 com.apple.iWork.Pages.plist file from Time Machine, make a backup of the one that is in your login directory/Library/Preferences folder, and copy the retrieved plist here. Restarting Pages ’09 v4.3 should reveal your auto-correction settings in the Pages preferences.
Look back in your Time Machine backups before the date that you installed (if you installed) Pages v5. Now, you need to look in the right place.
login directory/Library/Containers. Right click on com.apple.iWork.Pages, and show package contents. Now continue ... Data/Library/Preferences. Here you will find the com.apple.iWork.Pages.plist that contains your auto-correction items. It is this file that you want to put back into the first paragraph location. It is a binary file, so you cannot just open it in a normal editor, if you are so inclined.
If you want to verify that this plist has your auto-correction settings, get the free TextWrangler application from the OS X App Store, and use it to open the plist file. Once the file is opened, press command+F to initiate a find operation.
Select the following keyword and copy/paste into the upper part of the Find dialog, then press Find All.
kSFWPAutoSubstitutionArrayProperty
A new window will open with the found property. Single-click the result line, and your list of auto-corrections will appear below in structured XML syntax. If these are the items you seek, simply quit TextWrangler, and proceed with paragraph 3.
You may have to try a few Time Machine backup days to locate the plist you need. Tedious at best.
Good luck.
