Eric,
I recently succeeded with an upgrade of 5.1.4 => 5.2.3. I hope some of my notes will help you. I didn't upgrade AOLServer so I don't know what to tell you there, except that you might try upgrading to 4.0.10 and OpenACS 5.2 at the same time.
Note that you'll need to dump and import your database a few times with 7.4.13 and then 8.0.7 to convert everything properly.
Ryan
