So I managed to find some time to take the snorkel off today and as expected there is no sight of anything like an air filter, it's just piped straight to the turbo.
While it was off, I got a picture inside the turbo, the blades seem damaged, what do you lot think? Is it OK?
I'm going to order some 75mm flexi pipes and an air filter as well as the cyclone breather connection so I can sort all that out next weekend. In the meantime I've rigged up a makeshift filter in the snorkel.
Looks like the blades have been fouling on something. Was there any sign of foreign objects or debris in the pipe? They can get a bit polished from fine grit in the air, but this looks like they've been colliding with something larger.