UPDATE...
I have contacted Westfalia Germany who replied and gave me the contact for Westfalia France.
Westfalia France have requsted that I go through a Mercedes Dealer to request - even though these are shown as out of stock and made of Unobtanium.
Mercedes Benz South West have the part number and are going to contact Westfalia France requesting them for me..
I will let you know how this goes...