Have the same car you have and i changed my fluid a while back when I also felt a funny 2-3 shift.

Drainen both pan and tourqe converter, color looked like yours.
I changed the filter and 2 orings at the electric connector, pan gasket, copper seals and about 8 litres of MB oil.

It was a bit harsh in the shifts after the change but it's like new now.

My list:
8 L oil A 001 989 210 310
Gasket A 140 271 00 80
Filter A 140 277 00 95
Seal ring (Pan plug) N 007 603 010 112
Seal ring (Converter) N 007 603 010 100

Preventive:
Seal ring (connector) A 026 997 41 48
Seal ring (connector) A 026 997 40 48

__________________
/Per

MB E300TDT -98