Today was a good day.
Headed down to Rentech. Mike lent me a little 1.2 to smoke around in and while he investigated, I subjected myself to Ikea during half term..
Anyway, timing was 6-8 degrees out, the main dealer had managed not to fit an oil seal to the dephaser and the cat's buggered. Mike fixed everything bar the cat and for less than £165.
Result is linear power all the way to the limiter, much smoother throughout and pulling like a b**ch. Not sure how many missing horsepowers were rounded up but my guess is quite a few.
Just need to decide now whether to replace the cat or go 182 manifold and decat but I'm really, really pleased - car now drives properly hard and is transformed.