Here's your site:
http://sheldonbrown.com/vrbn-a-f.html#austro-daimler
I'll excerpt a bit but you should read the whole article:
"The company also introduced the Vent Noir. A step below the Team frameset, it had a very unique feature. The frame went through a "secret process" which made it impervious to scratches. It was not painted. From what we could tell, it was hard-chromed (the type of chrome you use on engine crankshaft journals, not the kind for hubcaps), and then some sort of anodizing on top. You could take a knife or a file, and you couldn't scratch it. The factory never did tell us what they did. But it worked!"
Nice bike! One of the better looking ones I've seen. Btw I have a thread going about the Moto. you passed up. While partial to Motos I can't blame you. Vent Noirs don't show up that often.