Seems pretty messed up situation. From my experience, relying on your 14 year old disk to not have written on top of your private keys, usually doesn't go well.

I have never helped someone recover deleted files, so I am not the best to help you in this, but I'd absolutely attempt to recover anything in there. I mean, we're talking about at least 50 BTC; that is a shitload amount of money. The first thing I'd do is use software which allows you to make quick searches on the drive, and I'd look for "wallet.dat". If that does not work, then chances aren't with your side. You should then start searching for uncompressed public keys I guess?