Hello, i asked the same question recently, and was surprised to hear that footwell carpets only appeared in 280's. Seems 230's and 250's had rubber mats. Carpets are now available for all models, i assume because in the 21st century drivers expect a bit more comfort and luxury, if you've ever driven a van with rubber mats in, you'll see that they rapidly become dirty and hold moisture and grit, and damage and tear easily, and it's not a particularly nice place to spend any time in for you or your passenger
Rubber mats are still available, and so for the sake of authenticity, these can be fitted and then covered by carpet mats, or Cocomats, but in my opinion, unless you have original mats, why bother paying out for new and then covering them with carpet, unless it's a show car