Dave,
First of all using TM to create 'roll back' backups isn't the best idea... TM is good for incremental backups and single or multiple file retrievals but for full backups and restores it's best to use a Hard Drive clone program such as Carbon Copy Cloner or my personal choice SuperDuper! to make a cloned image.
http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html
You will see why later on in this post.....
However, if a TM backup all is what we have to work with then we will just have to make the most of it 🙂
When you use the TM Recovery method.. (Restart your Mac and press CMD + R upon Startup) You can chose restore from TM Backup and in the window that opens to show your various backups it not only shows the date and time.. but also the OS X version at the time of that backup....
Make sure you have made a manual separate backup of any personal files/projects/photos etc to an external drive of some kind.. that you have created since that particular backup you are restoring from.. prior to doing the actual recovery otherwise you will lose those files forever... as they will be wiped out by the restore process.
Note: After recovery.... you may find you must for example.. re-register some of your 3rd party plugins.. or even reinstall them.. as TM does not fully and perfectly restore all files/settings... hence the suggestion in the future... to make a Clone backup instead of a TM one... before upgrading OS X or Logic for that matter... as a cloned backup is like an exact mirror image of the system disk and therefore when you restore using that you get a perfect outcome without any missing files or settings that need to be recreated or reinstalled.
TM does a okay job and so it's good to have at least that form of backup if nothing else is available... but be ready to do some extra work to get everything back up and running afterwards... Nothing terrible.. just extra work.
Cheers..
Nigel