I wouldn't touch the evaporator if your a/c is working fine. On later W124's, my MB tech tells me that evap failures are the exception, not the rule.

As a general rule, common failure parts on your chassis are: wiring harnesses and throttle actuators.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".