I was given a 'Robert Klaas' Black Angus for my birthday a few months back. It was sold by a UK distributer as being made from 'High carbon Solingen steel', so when I saw it was marked 'Inox' and 'Made in Italy', I contacted him. Unfortunately, the man was so clueless he thought that 'Inox' wasn't stainless, but Uncle Andi kindly contacted Robert Klass to enquire about the steel. It seems that the Brown Mule and Black Angus knives, while carrying a Robert Klaas tang stamp have little if anything to do with the company (or with Solingen). They are licensed to an American company, who currently gets the knives made in Italy. Looks like they get them made by Antonini. Be interesting to see how the Antonini and 'Robert Klaas' knives compare price wise.
Edit - Just to add, according to an e-mail between the American distributor and UK retailer I had sight of, both the Black Angus and Brown Mule are currently only being produced in stainless.