Thanks; I'll document everything and post photos etc. will also try to enter into the tech manual (previous attemps at mastering wiki speak were not successfull, must be some sort of mental block...). I am expecting this job to have a major impact on the overall appearance of the car for not too much money and without getting my hands greasy, but that may be wishful thinking. Anyway after having lived for 14 years with carpet I wasn't really fond of, I look forward to the 'out with the old, in with the new'.
I decided to stay with the same colors (blue on blue) because I don't want to replace all the MB tex on the doors, dashboard etc, and it seems most good looking interiors have the same colors for carpeting and covers, but that is another available option and I'm sure really changes the look.
A question I still have to tackle is whether I want to put in sound/heat insulation underneath the carpets. I'm thinking yes but will do some research first. I recall there was a lot of discussion a year or two ago on that here.