Severe power loss - help needed!

Thanks guys for all your responses, now here is the good news.
Found the circlip missing on the wastegate, now back to full power! I have not been for a decent drive yet, but planning a trip to Agnes Waters on Sunday for a few days with the boat, so will give an update on my return. It will be interesting to see what happens to the fuel consumption, hopefully it will return to normal at around 10.0L/100 km (it has been around 13.5L over the last few weeks).

Thanks again to all.
Cloughy

As promised, update after 500km trip - the vehicle is back to full power, but have not seen an improvement in fuel consumption. This is most likely because it pulls so well, I forgot I had the boat on the back!

Thanks guys,
Cloughy