Sorry it’s taken me so long to reply but I am very busy trying to create a more modern website.
I understand you wanting to keep your original system but make sure you store it well.
You will need a full system though as the silencers and downpipes are one piece.
You can try BSM
They list 2 into 2 systems for the LTD models (K and LTD). I have a system suitable for a B model so I know they did make them. Worth a try.
The only other place I know for New is in Germany I believe. I am struggling to find details but I will keep hunting