Got the mk7 going back in for a retest tomorrow. Two of the fails took a grand total of about 45 seconds to fix, most of which was taking the wheel off. It failed on rear n/s brake binding excessively and handbrake doesn't meet efficiency (or however it's worded).
When I took the wheel off, I saw that the handbrake lever on the caliper was right up to the cable stay. I gave it a scoosh with penetrating oil and it spring back straight away. I suspect when I changed the disc and pads on that side I must have pulled the handbrake before pressing the pedal. Once the lever was back in it's proper position, the wheel turned nice and easy and the handbrake lever felt much better.
The brake pipe that it failed on (it passed on it's previous MOT just before I got it, so I didn't bother to check it) fell apart when I touched it so just as well it failed.... Also a good lesson not to assume something is fine just because a tester passed it on an MOT!
It was the front driver's side. Absolutely impossible to fit without removing the engine and subframe, so I made up the repair section up to just under the servo and cut the existing one and joined them with a union. If I don't say so myself, it is a beautiful bit of pipework!
It's booked in for it's retest tomorrow lunchtime. The garage are still too busy to do the tracking but I'm "working from home" tomorrow so will take it to the local tyre fitter to get done after the MOT.