I'm not sure if this helps you, but in terms of bumper numbers, the Prime Portal has some pictures where you can see them on various German vehicles. Might help with trying to decode the format if there isn't simply someone around here who has an actual source.
http://data3.primeportal.net/tanks/m...5_06_of_28.jpg
http://data3.primeportal.net/tanks/m...5_23_of_28.jpg
http://data3.primeportal.net/tanks/m...5_13_of_28.jpg