I just got the correct Wurth paint from Goodspeed Motoring in Central CA. They have a great online store.
there are two Wurth paints, that are close, White and Silver. Later German cars use the Wurth Silver Wheel paint. I have done Boxster and newer 911 wheels with this, and it looks great. But, its a little darker and hasd a lot more metal flake in it than the original finish of older wheels.
I just refinished my later-style steel wheels with Wurth White wheel paint. It looks exactly like the original finish. I bet it will be closer to your correct Pedrini finish. But, if you are not looking for exact OE look, the Wurth Silver is a great look.
Call or check out Goodspeed online.
And here is my previous post about my wheel refinish.
http://www.914world.com/bbs2/index.php?showtopic=110752