I think 41 degrees is about as cold as you'll ever see in an older Mercedes. All the way back to at least the 123 they used an evaporator temperature sensor to regulate the cycling of the compressor. Mercedes is very conservative - they cycle off the compressor well before the evaporator drops to freezing temperatures. If you're seeing 41 degree vent temps, the compressor is probably cycling to prevent it from getting any colder. I've read that Europeans don't like the gale force cold air to which Americans aspire - hence the rather tepid a/c performance of the older cars...