Noblex (Germany):
URL is right, seems that they are currently updating their homepage.

Another article about this company (history and current product programme):

Phenix (China):



Arca Swiss:
AFAIK no own homepage, but:

And AFAIK Plaubel (Germany) is still producing LF cameras. But they don't have a website.

Edit: Sorry David, time overlapping with your post (Alpa, Arca Swiss)