380 Seat Height Spring is loose

[twochaps]

The passenger seat on my 380SL was impossible to adjust forward/backward and up/down. I removed the seat and found that the rails were solid with (I guess) old lubricant. I cleaned the old stuff out and regressed the rails/runners. So far A OK! Next I found that the BIG spring that looks to control the seat up/down adjustment was only connected at one end! I have a feeling the previous owner tried to fix the unit and couldn't. So I said, I'll just finish the job. Not a good idea. I spent probably 2 hours trying to attach the loose end of the spring to the under seat opening in the frame. Mission Impossible! Can this be done by a DIY person? Is there any special tool to use for this job? Any one know how this should be done?
Any ideas will be appreciated.
Thanks