The correct carpet for the 230SL was a wool square weave - it was the seat pads which contained horsehair I think. GAHH are reportedly pretty good quality. I'm ordering a grey square weave carpet set and black leather interior from them this week. While not technically correct for my year (1969), I prefer the look of the wool square weave over the multi-loop blend which was originally installed in my vehicle.
Steve Hamilton
1969 280SL silver
Vancouver, BC