Missing files that were renamed?! Help!

Dear friends, for some reason some photos were renamed and now LRCC cannot link them anymore. I performed a TimeMachine restore and found that they were moved and renamed don't know why. That's cool I thought...restored from backup but there are only 140X140 files maybe LR thumbnails ?!

The original files are somewhere in my drives but how can I spot them if they are renamed?? IS there a way by using a thirds software to find identical files by image comparison ? I mean, comparing the image itself??

Thanking in advance,

Sergio