Peter,

What you want to do is use the car's momentum if you have it parked on a hill to turn the engine far enough so the broken teeth on the ring gear move away from the starter's pinion gear engagement area. Once you get the engine to turn just a little, you turn the key to engage the starter and you will find it engages like it used to, but, to avoid driving on the starter, you have to push the clutch back in. Or, you can just let it roll forward a bit, then let the clutch out with the car in third, and stop after about six or 8 inches. Then try starting the same old way. This will get you about a quarter turn on the engine, and should present a sound set of teeth to the starter pinion so it will work fine.

If you are parked on level ground, just put the car in third or fourth gear and push it forward several inches against the engine compression. Then try to start it. If you turn the engine over far enough to have the flywheel/ring gear present whole teeth to the starter pinion, the starter will function normally. And getting the car to move is no big deal, as this is how I always adjust valves - put it in third and pull the car towards me from the front, watching the cam lobes.

If you are on a hill with the nose up all this becomes more difficult since the reverse gearing is so high. It is still feasible but you need some room, not something you would attempt on typical NYC curbside parking on the street....

Good luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)