68 Barracuda fastback trunk recoil adjustment

I've got a 68 fastback and the trunk doesn't want to stay open unless the car parked on a perfectly flat spot or on a slight downhill slope. I have to use a stick to prop it open. I read in the 68 Plymouth shop manual that the trunk recoil springs and hinges can be adjusted on the fastbacks only (they don't have torsion springs). The manual is kind of vague about how to do it. It says "loosen the screw at the slotted end of the tension arm and move then tension arm with an open ended wrench in the desired position." The diagrams in the manual don't exactly show what they're talking about (or maybe they do and I'm not seeing it). Furthermore, the trunk hinges are tucked way up in there and are difficult to see and even harder to reach. I'm taking the back of the car apart in an attempt to do this. I was just wondering if anyone else has done this and has pics of the fastback hinges and/or can explain to me how this adjustment works. Last thing I want to do is accidentally unwind the tension spring on hinge that's tough to reach. ;) Any advice or helpful information would be appreciated. Thanks.

right after I posted this... I found the following picture on ebay where I circled what I think I need to adjust. Nothing in manual look like that...

hinge.png