A lot of Parkwood's stock still runs extension springs mounted along the horizontal track, and those are more forgiving to work around than a torsion bar - but forgiving isn't the same as safe. If a spring has already let go, the cable and pulley are usually still under tension somewhere in the system, and that's the part that hurts people.
What you can reasonably do yourself: check that the track bolts haven't backed out, clear debris from the roller path, and test whether the door is out of balance by disconnecting the opener and lifting by hand - it should hold steady at waist height. If it drops or shoots up, the spring tension is off and that's not a bracket-tightening job.
We'll be straight with you: we don't recommend spring replacement or cable work as a DIY project on a door this age, because the failure mode on old extension-spring hardware isn't gradual - it lets go all at once. If you're comfortable with basic maintenance, do that part. Leave the tensioned parts to a call.