the parking brake cables need to be adjusted along with the automatic adjusters in the rear drums - if they are too loose the brakes will feel dead at the pedal and the hand brake will not be effective.
The brakes need to be serviced and antisieze put on the adjuster threads - then the handbrake single link or twin link needs to be adjusted so they have all free play - raise the lever two clicks - then ask the mechanic to adjust the adjuster wheel so they just drag the drum slightly. Finally for correct height of handbrake - adjust the brake cables again for approximate 6 or 7 clicks for the car to jam. This way - when you release the handbrake fully - the wheels will spin free with no contact