Your car's code is D69 - Gris Platine.
It is possible to make a reasonable effort at disguising this damage yourself, here's what I would suggest you do;
EDIT: a very fine artist's brush could also be used.
Thanks a lot for the expert advice, I am definately going to give it a go this weekend and report back.
Also big thanks for everyone that has replied. I didn't expect so many helpful comments in such a short time... Cheers!