My rundown on the Winton test day will follow this post but first I want to show you what went wrong.
It seems the valve (or piston) in the wastegate has picked up on the bore and seized, when I got home I had a chance to pull this apart and find the issue.
I have used these precision wastegates for a while now, I tore a diaphram in one a long time ago in my 180SX, I pulled this wastegate apart and used it for spares. The valve was in perfect condition and after inserting it worked a treat!