Hymer Van 522 exhaust

We have a Hymer Van 522 on a 2006 Ford Transit base (registered in 2006 but we think manufactured in 2005). We need to replace the tail pipe of the exhaust. This is a Ford part but our local Ford dealer is unable to help us. They say that:
1. they cannot identify with certainty which exhaust it is on their stock list;
2. they have not sold one of that design for years;
3. there are none in the country and they would have to order one from Germany (where the van was manufactured) and even then could not guarantee that it would be the correct part!
4. It isn't the usual Transit exhaust as it has to curl around the step retainer below the habitation door.

I have also been in touch with Hymer dealers who have confirmed that it is a Ford part, not a Hymer part.

The local Ford dealer advises me to contact a specialist workshop who makes customised exhausts for rally cars, classic cars etc. I find it hard to believe that large operations like Ford and Hymer cannot supply a standard part. Has anyone else met this or a similar problem?

Thanks for your help.