There is no utility for HFS to recreate the partition map like you can with MBR (FAT-NTFS). Your only hope at this point is to use what you used to recover the work files and transfer them to another drive. Also at this point since you've been messing with the formatting so much there is probably no viable backup directory on the drive either for data recovery apps to parse file types etc.

Sorry to hear of you predicament. All I can suggest is next time don't mess with partition tables unless you have a backup of the drive. I would never consider any major maintenance without a backup.
The thing is, once I tried to use Tiger to repartition my external HDD like I used to do with Snow Leopard, it's partition table got screwed up! After some reading on the web I found out Tiger's partition scheme is different but it was too late.
Just curious, what did you use to do that? iPartition?