Easily done. First, get yourself the Rev 233 update:
http://www.projecteq.net/phpBB2/viewtopic.php?t=4612 You're only using this to update your db, don't worry about quests or anything. The 1110a DB is very old, so that might be why you are having trouble. This assume you have not changed your db name, user, or password. If you have, then the update will fail as it depends on the settings the original installer provided. You will know if it failed if the DOS window that sources the DB doesn't stay up for at least a minute or so.
From there, grab the newest PEQ CVS. Source drop_system.sql, then source in the gz file after you unpack it. Go into the updates folder and run EVERY update from 233 up. So, start at Rev247 and go through Rev294. DO NOT skip right to the end, or run any other updates before 247. Also, don't source any sql from the EQEmu SVN, including from the changelog. Everything you need is handled by PEQ CVS.
Then, grab the newest quests from PEQ Quests CVS, and the newest server build from the EQEmu SVN and you should be set.
While all of your character data will be safe, your content will be lost. There is no way to preserve that other than keeping a sql record of every change you make and source it after you resource the content. PEQ makes so many changes to its database daily that there is no way we can offer individual table changes.