Thanks a lot man! I'm not really sure what you mean with "carbon scoring"? Dry pastel is sold as chalks in all hobby and art stores. I can't think of any special brand that's better then others but you want to get them as soft as possible, but DON'T buy oil pastels by misstake! I have only had good results with the colored ones on light surfaces like white or grey, but I have been able to use black with great results on almost everything. Remember that the powder only sticks on matt paint and not gloss.
I don't know how to post pics on this site ( I guess I'm not allowed to host them with wackychimp here) but if somebody could host pics for me I'll be more then happy to take pics of the chalks and how you apply them, the results of different techniques and so on!
Just let me know!
Steve.