I've got it back and crikey it's good.
The specialist kept the bits for me to have a look at (but I forgot to take pictures
). The water pump was broken, with a massive crack, both idlers and the tensioner were "gritty" sounding and the collar from the dogbone just fell out.
The damage? £991.70 inc VAT. £350 for labour. I think it's a fair bill and I'm happy using (and recommending) cloverleaf in Gloucester.
The results? Much quieter in all the right ways. The new MAF has improved the performance of the car greatly. I did have a chance to test this out on the way back and terrified an old Rover driver as I went past accelerating though 6k rpm.
I also spotted an even rarer Italian car on the way back. A Pagani Zonda C12S. I overtook him.
He was stuck in a queue, though.
The only downside is that I can feel that the shocks are worse than I thought. I'll have to get them upgraded soon but I'll probably have to wait for bonus time.