Okay, I finally got round to changing the springs and dampers the other day. Pretty straight forward, without issues. Though there's still a slight rattle from the rear, a tired droplink I suspect, as they are both tightened up.
Ride height is now approx 425mm, which is lower than I expected but actually what I wanted. My driveway woefully needs replacing, so finding good flat spot to measure isn't viable. Pics attached of before and after.
Thanks a lot for the advice Mr B
Cheers
Neil