Hi,
I hope I can help you out cause I built this kit as my first model. The color you use on the car should be black for the most part. For the mud guard and the other parts that are made of plastic in real life, you use semi gloss black or flat black based on your personal preference. The best way to find out is to check out some real pictures of the car.
As for Mahagony and Red Madder, you can check out the color chart for Gunze Sangyo paints:
http://www.ipmsstockholm.org/colorch...rcolor_map.htm
Mahagony is 42 and Red Madder is 68
I hope this helps.
Winston