Hello, my name is Mike and I can help you with this.
You have a broken gear or drive cable in the seat frame assembly. Unfortunately your repair actions will be dictated by what parts you are able to obtain. You will need to watch auctions and such places as ebay and cragslist, search online salvage yards, and online parts houses specializing in oldsmobile parts.
You could remove the seat and flip it over to identify what is broken. often you gan get the seat flipped around, or raised up on blocks so you can see. operate the motor and look for what part is not moving. perhaps something came apart which could be made to work again.
I hope this helps you with your problem.
Thanks,
Mike
ASE Certified Technician
20 years experience, all makes and models.