UPDATE...
My car went upto GMC on the 6th May and Ive been up to see it today - its been away for 4 months!! I've settled my bill with John and will be arranging for someone to trailer the car home to me asap, so some further development and fettling can commence.
John's done some pretty trick work to the engine and turbo setup, which I'm very happy with. There are a few niggles with the component match-up though, which I'm going to see if I can sort before making any drastic changes.
The turbo is supposed to flow upto ~1.5bar of boost, but on my setup its peaking at just over 1bar, then dropping. This wasn't planned! There are a number of culprits, but one known issue is the intercooler. With an alternative intercooler, the power has been 0.2-0.3bar higher through the rev range. So a larger, less restrictive item needs to be on the cards! Extra cooling would also help inlet temps and allow the map to be adjusted to bring power in stronger earlier on.
John has struggled to get my car to keep traction on the rollers. Partly this will be due to my tyres, which are rock hard as they've not moved in quite a few years! lol John tried to fit other wheels/tyres to do a proper power run, but none of his rims would fit over the 325mm discs I have.

On paper, the engine is producing ~220@wheels with wheelspin. John thinks this is more like 260@wheels on the road. Time will tell
The brakes - a bit of a work in progress I think. We've tried something different and the setup is not quite right. A bit of head scratching to be done I think. All opinions welcome
I've uploaded a video of some of the digicam clips I took during the rolling road mock-up today. This wasn't done to try and prove max power or anything, it was just to give me an idea of how its running. It sounds NICE
VIDEO >>>
Rolling road test run at GMC
Hopefully I'll have the car back this week, or early next. Then I can start tinkering again. Here's a couple of pics...