OK so I guess this will be the final update to the thread. I picked the car up this evening and it seems they have done a good job. Makes good power still and no funny noises so I'm pleased with that.
They gave me all of the old parts and to my surprise there was an aux belt tensioner and pulley in there, so it looks like they have replaced the full aux kit anyway, unless the cam belt has an identical tensioner to the aux belt?
I only asked for the cam belt and dephaser with a new aux belt so looks like this is an added bonus.
They mentioned the old dephaser was starting to stick so a good job I got it changed as initially they recommended leaving it alone. I have the old dephaser here, is there anyway I can test for this sticking with it off the car?
Overall paid £670 which I know is probably a couple of hundred more than I would have paid at an independent, but I didn't have to pay fuel or accomodation costs which I would most likely have done if I was taking it to Mick/Fred/Dan, not to mention possibly having to take time off work depending on opening hours.