Thanks for the comments everyone ☺️
One thing I will add that's not in the photos - the exhaust. The original secondary's were still there(!), but it was badly welded to a horrible ugly steel press bent rear section with bypass mufflers fitted. The rear muffler was rusted out, so I spoke to the owner about a new system...
I carefully cut away the old system from where it joined the secondary's, then Tig welded on a step joint. Following this I had the secondary's media blasted, then I gave them a coat of exhaust paint.
The rest of the new system I made out of 304 stainless steel