I've read many times on this site that the shop time to replace an evaporator in a W124 is 22.5 hours.

I agree with Larry. Stick with R12. Yeah, it may be cheaper to recharge the system with r134a if you develop a leak, but your a/c will never blow as cool as it will with R12, and you'll regret it.

Trust me - been there, done that.

__________________
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".