I'm so sorry to hear about your saves. :(
No one but other sim players can understand the strong attachments we form with our sims and the work we put into them. I know how you feel about not being able to go back there and do a lot of it all over again. If you do, I like your idea of saving yourself the anguish and just age them up and add their final traits.
Once you started having problems with your game, things seemed to just pile up and now this. Well, it's never easy to pick ourselves up, dust ourselves off, and continue on, but sometimes our game doesn't leave us a choice. I look forward to any updates on this. Good luck sorting it all out. Did you ever find your sim self?