Hi Benno. There's been a bit of discussion about this in the past -
CLICKA couple of options mentioned here, but easiest one is the VHT Satin Black, which is a nearly perfect match for the original black.
Big bonus is that it comes in a can, so no mixing required.
The Search button is our best tool on here. Just click on it and type in "Engine paint"
It'll then provide a list of posts where it's been mentioned.