i did some research with PB motorsport earlier this year. i had the understanding my extractors were a PB wrc spec. But the guy at PB said they were genuine syms and were approx $3-4k new and syms were the ones they used on the early wrc cars. freeflowing small S/S tubes.
I now have twin scroll s/s headers which are better still. extra 15kw atw without doing anything else.