Phantom (and all),

Thank you for the info! In fact I just signed on to explain how I ended up fixing the seat...

First of all I was mistaken about the cable being broken, when I removed the cable from the motor the other evening it appeared that the end was broken but what I was actually seeing was just a blob of grease. (The cable was quite far p inside the sheath.)
I fixed the cable by heating the metal end and pulling it off with pliers, trimming the sheath down about 1/2in and slipping the heated end back on.

Now for the cause of the twisting: Somehow the square bar/rod that runs across the seat between the two gearboxes had come out of the right side gears on the seat. (It slipped to the left in other words.) With some coaxing I was able to get the seat lined up and slide the rod back into the pivot point of the seat. "Easy as cake!" as some would say...

So I really had two problems, a cable sheath that needed to be cut down and a rod that needed to be put back in its place. I don't know how the rod moved and it isn't clear what keeps it in place now but it doesn't seem likely to come loose again. BTW the clip on the bar is in place but doesn't look like it is serving a function, I could move the bar out of place again if I wanted to without removing the clip.

Thanks again for the help, I hope this saves someone else time in the future.
-Pellucid