Thanks for the links I'll be sure to read and digest. So I think I found what the tester was failing the car on. If I yank on the hand brake it goes full travel, as opposed to just a nice normal putting brake on. Anyway, I'd disconnected the nearside brake and hand a go on my hand brake which now felt normal. I've since replaced the brake cable. Interestingly there's a half inch bolt that needs to come off, this was rusted badly I thought it was going to be a sod to get off. The hardest thing was actually pulling the cable through and out. Haynes suggest a method of using a spanner to compress the locking tabs. My method, use leatherman to snap locking tabs, then pull through. Installation is easy, I used the handbrake to pull the bit with the locking tabs through the hole. To try and do it manually is next to impossible. Results as follows, hand brake no longer goes full lock. it stops the car rocking when put into Park. When I'm on an incline I need 2 or 3 extra clicks to stop it rolling away. However there's still something not quite right, I may bite the bullet and put a new cable on the offside. The bit that's not quite right is that when I get my extra clicks in, I'm very close to running out of travel. As I get 10 days for a retest, I may put it in as is and go from there.