sorry for the late reply: it was not too difficult: I filled out the CC-application form, sent to LBB and got a reply-letter that - as I have no residency in Germany - I need to send a copy of my passport approved by a notary or consulate. I went to my Austrian consulate in Zurich who stamped the passport copy, which was then accepted by LBB and I received my (Platinum) CC within approx. 2 weeks.
no personal income statements or bank confirmations were needed.
That's great!
Did you have to produce proof of residency in Switzerland or Austria at any stage? Or anything else whatsoever other than the passport approval?