Good find! There have been a few posts on here about the difficulty in finding touch up paint for black magic. Sounds like this may be the answer.
 
No worries. I'm guessing nobody has tried it in that case, so I'll take the plunge and let you know how it looks.
 
iirc it's not the same paint, either that or I've not mixed it up correctly, it didn't have the same metallic look as the Seat Black Magic paint and made the stone chips on my car really stand out afterwards.

You can order the paint from the dealers so that may be the easier option, at least then it should be the same paint, or see if a friendly bodyshop will mix some to your paint code.
 
Can't help with the colour match, but you are not going to get rid of rust with a clay bar!

For starters, rust will usually have gone under the paint around the chip, so to do it properly you need to treat ALL the affected metal, or else it will ust continue (a little slower) under the new paint you put on it. You need to get right back to good metal, treat it with something like 'Kill Rust' (hammerite product), then cover that with a base layer (primer), then colour then clearcoat.
 
The Seat colourcode C9Z Negro magico perlado= exactly the same as VW LC9Z Black magic perl=exactly the same as Skoda 9910 Black magic perl

grtz Dennis
 
I have used the Skoda Black Magic paint from halfords for about a year on any stone chips.
Seems a good match to me.