I wrote to the dealer yesterday evening asking them to double check if they can actually supply a touch up pen of Oxide Grey as another member here said that he'd wanted to buy one and was told that colour way was unavailable to purchase. But that was a year ago.
Got no reply back from the dealer today, so that's handy. I will phone them tomorrow morning from work, should be relatively quiet then.
I have some experience with painting model cars with acrylics. Think I may just apply the paint myself, build it up in layers as bmnut suggested and once ready and cured I'll get a detailer to polish it back.
Wasted time after work today going through rush hour traffic only to find the detailer I was going to see had already shut up shop and buggered off for the day by 16:00. Awesome!
