Iam looking at the Mann + Hummel parts book, they being Oem to MB.

The following filters are listed

w124 01/85 to 12/85 w719/13 engine m103.980

w124 6/85 to 8/92 w719/13 engine m103.983

w124 08/85 to 08/92 w719/13 engine m103.983 KAT 08/85 to 08/92

w124 09/86 to 06/93 w719/3 engine m103.985

w124 09/86 to 06/93 w719/13 engine m103.983

w124 09/88 to 08/92 hu727/1 engine m104.980

It can be seen that the 300e used two types of filters, I will post in a minute and give you the MB part numbers

Regards

Col Downunder