Someone on here has tried a softer compound rear pads and reported the handbrake as being more effective with no adverse other effects. I can't remember who it was now though doh.

Later - this one..

Originally Posted By hARPpy chappie
Personally I haven't got a clue what a 'handbrake cable compensator' is or were to find a 'rivnut' but I am able to report that the handbrake issue on my ARP4 was eventually resolved by the simple expedient of fitting softer brake pads. The handbrake now passes the MOT test. Nice. Thanks to Krazy Horse as ever.

PaulJ KH will be able to give you a part number I would have thought.

2009 4/4 Sport Henrietta
1999 Indigo Blue +8
2009 4/4 Sport Green prev
1993 Con Green +8 prev