Haybine Torsion bar stuck

I have a 467 Haybine, and the torsion bar for the top crimp roll on the outboard side seems to be stuck. I finished out the second cutting last season by disconnecting the linkage and using about 10 rubber bungee cords hooked through the top roll clevis hole and wrapped around the rear axle to supply the closing pressure (and actually this worked amazingly well).

 

Of course, life got in the way over the winter and now I've finally got it in the shop with only got a couple of weeks before I'll need to start cutting. The tension adjustment in the center under the cutter bar isn't rusted too bad. I wish there was some sort of service manual for the Haybine... 

 

I'm sure I can figure it out but I'd like to avoid doing something stupid. Any suggestions/pointers/tips/warnings before I start trying to take it apart and get it working again? 

Haybine Torsion bar stuck