Steel Icarus
ersatz maven
I was at a talk by Mark Herbert (producer of DMS) a while ago and he mentioned that up until the scene where the characters Richard and Sonny first meet (when sonny is driving past in the 2CV) neither of them had actually met each other IRL up until that point, and both had been getting wound up by the rest of the crew about how mad each of the other was. I think Sonny already had a reputation as a hard man due to being a boxer IRL.
The dialogue between them in that scene was also improvised.
It's brilliant, too. Cos it's not aggressive, not really. Even the "I was that close to slicin' it" line is fairly matter-of-fact.