Are they not just standard late 90's alloy four pots as fitted to e, s, and sl classes? Lots of c36's being broken with huge four pots that are a bolt on mod as most of the bigger engined 202's use the same steering knuckles.
Getting the knuckles off and machined can also be a lot more difficult than the guy makes it sound.
A set of as new SL65 8 pot calipers went for £500 last week on ebay!