I'm sorry to infrom you that I didn't accomplish anything. I've tried to restore but hadn't time to look up for other solutions. After some lost nights banging my head on the wall, I have started from begining, converting VHS except some videos that were gone forever.
I've tried to convert to other formats but that didn't work. Now, I'm dubbing to DVD video in HQ (but haven't noticed any difference in standard quality). And it takes weeks to convert all VHS to digital quality. It would be awsome if I could keep direct quality when converting. Now trying to contact one of Sony Engineers through my sisters friend. If i find someone, and achieve something, i'll post here. Till then, best regards and best luck with videos.
P.S. Have you tried contacting one of companies that recover lost data? Or they use same tools like we do. Maybe they better understand the problem regarding formats etc. But if sony doesn't know, nobody knows. Cheers