In the future, if you have an old service invoice from the dealer, look in the vehicle area of the ticket for "RSC" (which stands for radio security code) and there will be the numbers you need to recode your system.
Only my W124 had the numbers incribed in the owner's manual...I discovered the invoice tip only after realizing that the other two MBs didn't have it written down anywhere!
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car