Since your car is an early 250SL, you should have a version 3 master cylinder.
However, this has been superseded by version 4 which is what is currently available from MB (part number A002 430 28 01).
The actual change to version 4 was introduced in September 1967 (chassis number 043 xx 002980 onwards).
The master cylinder should have only 3 ports, the rearmost one for the single line to the rear brakes and 2 ports for the front brake circuit.
On earlier cars, the bottom port (front brake circuit) is blocked off with a bolt and a copper crush washer as these cars have a brass T-junction mounted on the fender that splits the lines to the respective front brakes.
As for the booster, the MB part number is A000 430 55 30. Made by ATE and also known as a T51/200 unit.