According to the Beemer Shop's web site, they are "the west coast importer". The inference is that there are importers east of them; it would not appear that they are N.America's exclusive dealer the way I read it.
According to Wilbers own web site...
Information about:
Klaus Huenecke
Mr. Huenecke is a trusted and reliable licensed dealer of Wilbers Products GmbH for some years now. From his office in New Jersey he started the Wilbers exploration of the USA. Due to his huge experiences with our shock absorbers and with our whole product range, he is THE expert in the USA you can turn to whenever you got servicing or installation questions. "
https://www.wilbers.de/usa/index_shop.html?index_start.htm
I thought I had read some months ago that the two had kissed and made up.