is there an adjustment on the cable or does the adjustment get done on the back of the caliper?

can't remember how these older cars work. my last one had a drum setup inside the disc. from memory i think the handbrake screws the piston in or something doesn't it?

pretty sure there is an adjustment up the front somewhere on the cable though.

There is an adjustment section under the the car in the middle where the cable has a join between front & back.
That section is a metal clip/bar with 2 nuts that hold the cable in,simple adjust to whats required

Mine needs doing. Got a shock a the other day when I pulled up my level drive. Pulled the handbrake all the way up, and proceeded to get my things together to get out, it was a good 20 seconds before I realized the car was still rolling forward!