I checked my ACC vacuum actuators last weekend, and at least 3 of them will hold no vacuum, including one of the center vents. Guess I may as well do the whole vacuum system as well as the evaporator. A couple of things I cannot seem to find in searching are:
1) How many 'y's, 't's etc are required in a complete ACC vacuum rebuild?
2) Will 15 metres of plastic vacuum hose replace every hose in the system? (just ACC, I already replaced the engine vacuum lines)
3) If I get the copper evaporator, it looks like I will separately need an expansion valve. Are there any other parts I will also need?

I am thinking about taking the old A/C hoses to the local hydraulic/AC hose place and having the rubber replaced. Any tips on this?

Lastly, should I get a rebuild kit for the compressor while I have the system depressurized? I currently have fairly cold air out of the two side vents, but since I am doing all the rest....?

...edit... this is on the 300e. I replaced the expansion valve and compressor on the 528 a couple of years ago and it blows about as cold as r134 will, which is why I will keep R12 in the Benz....