Got the new heating valve today...

Looks like new, the rubber inside the tube seems soft and in good shape. They said it came from a MB 300SL -89 and was the only used one that I could find in Sweden at this moment and I only paid 460 SEK (70$), got lucky I suppose since they didn't know how much it was worth.
Tested the function and now I can really finetune the heat both on the driver and passanger's side.

The new and the old one...

Ready for test...