So just thought I'd update with a video.
Mechanic just dropped my car off and sent me a video he took.
He said the wastegate was knackered hence needing a new turbo.
I went all out and bought a brand new one and not a recon turbo. He says it feels totally different, so looking forward to driving this again and hopefully fall back in love with it.
Anyway, a lot of cash later, here is the video of my knackered wastegate you hear the noise of in the video.
I've no idea what I'm looking at, but I'm guessing you shouldn't be able to do this with your finger?