Just to add to this, I Googled "Rindt 1970 Hockenheim" and came up with:
http://img1.auto-motor-und-sport.de/1970-Hockenheim-articleOpeningImage-4c0008fa-376385.jpg
http://www.rheingalerie-bonn.de/wp-content/uploads/2012/03/2.-August-1970.-Hockenheimring.-Grosser-Preis-von-Deutschland.-Jochen-Rindt.-.gif
Difficult to see it properly but it does look like the dial is silver or white and not black. I might be able to get higher resolution versions of the pictures I uploaded, will see what I can find.