It's not worth much.

The leaking injectors are likely just the soft return lines need replacing. You can get a stick of the hose for about $4.

The rear brakes have shoes for the emergency brake. They may simply need to be loosened up a bit.

Those not familiar with MB's, and sometimes those who are, can be fooled by the appearance of an old MB. The reason is that the paint, chrome trim and other cosmetic aspects of these cars are typically much longer lived than most other brands. This makes an old tired car, "look like new."

Be careful,