Hi Karl
Welcome to the site!
Interesting that even the motorhoming world is not immune to conspiracy theories!
What sort of parts are you looking for?
Have you tried the
Dethleffs Owners Club ? They have recently launched what they describe as a "tech helpline" for parts. The following is quoted from their site:
Help with parts and problems. June 2009 we have launched a new FREE Email-Back-By-Return tech helpline. Last year we helped over 63 members to stay mobile. Windscreens, upholstery, delivery, body parts for older Dethleffs, replacement water caps......Oh, and the perennial: Charging Systems! We have great contacts and we are not afraid to use them!!
They do state that you have to be a member of the club to use the helpline - membership is currently £15 a year and that also gets you various supplier discounts.
Hope that helps!
Cheers,
Mark.