Thanks for the advice chaps, in the end I got Holts firegum putty, as Volvo had some in their parts department when I picked up the door card fixings they ordered in for me.
So I slathered the putty around all the joints, the front silencer-extension pipe join I also got some stickyback metal tape, which I wound around the junction, smeared some putty on the blowing sode of the union and slipped the connecter sleeve over it all. Now, there is almost no blowing whatsoever, which I am quite cheefrul about. The engine is MUCH quieter and smoother now!
Also today I put the passenger door card back on, with the new clips. It now functions as a door and doesn't snag on the door seal!
I installed the new spray nozzles, one of the old ones snapped clean off before I applied hardly any pressure to remove it, so was on its way out anyway. However, as some of you quite rightly said, the connector valve is busted and spews water out all over everywhere, with no water actually reaching the nozzles. So i've ordere one of those.
My new winscreen washer reservoir caps also had arrived in the week too, so put these on.
I also picked up some new numberplates, went to Halfords as they were open, they were cheap, and not great quality either. I had to drill two new holes in the front bumper to screw into as the old screws were so rusty that the heads just sheared off!
Old
New
Old
New
So there probably won't be much more progress now until towards the end of September as we're off to France on Thursday. The MOT is due when we're away, but it'll have to wait until we get back as it's not quite ready yet!
Cheers,
Tom