Those PACE callipers look like these!
Mechanical Parking Brake Calipers
Ben, this winter has got to my old joints and progress has been very slow. The car has been sitting with the handbrake 'on' in an attempt to settle the cable and minimise slack. I hope to give it a final adjustment soon and determine the effectiveness.
I'm optimistic what I have will hold the car on a 1:5 slope (no chance of a 1st gear stall) and pass inspection but it's a long way from being a 'good' set up. The IPSCO callipers don't appear to offer a better mechanical advantage, nor a bigger pad area, but certainly appear to be a big step up in quality from mine.
I'd be interested to hear from PACE users.