I have stayed out of this discussion as you have gotten some good advise.
After reviewing the chain of events here I would refer you back to German Automotive's comment about the master cylinder. I agree with his assesment here. I also agree with Benzmac; I just filed my tangible tax form and nowhere in the $400,000 worth of tools and equiptment will you find brake lathes - WE NEVER TURN EUROPEAN ROTORS. Use them till they wear to min thickness and replace. They have around 0.040" on a new rotor, by the time you have any groove there is no where to go.
As to the vacuum line it is a common caualty to working in that area. An experienced MB tech will avoid the problem as he knows how fragile that old "brake booster vacuum supply hose" gets. If you need a number or someone in your area to trust let me know.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician
[This message has been edited by stevebfl (edited 04-09-2000).]