I have just had these manufactured in stainless steel part number 035 145 735 they are a top quality pipe made to very high standards & exceeding Audi spec.
They have taken a lot of work/testing to develop and so are not cheap but they are a fit and forget item you will never have to worry about again!
I'm also manufacturing new feed pipes but I guess these are a month away.
The return pipe will come with new gaskets and cost £300 + vat and are available now!
I also have new oil feed lines all stainless steel £300 + vat
www.quattrocorner.com