C & D are just the major services that will include things like ATF change, spark pugs changes etc at various time/mileage intervals - there is no mention of this work being done - important for a car with this mileage.
LWB vs SWB is down to opinion and need, but the extra legroom in the back makes for (IMHO) a much more complete car. I owned a SWB W140 S320 and regretted it everyday that I didn'thold out for a LWB version. There is such minimal performance differential, that would only be noticeable on paper.