I found a downpipe that will work for this swap from a friend. I will still need to find a spacer for it to clear the shift linkage. BFI sells them, but they are "out of stock for an unknown amount of time"
Here the difference between the TT downpipe I bought and the stock MK3 downpipe:
And the difference between the stock Mk3 and the one I fabricated..
And so the hunt continues for a final solution....