The gas flap on my 1981 380sl never locked, so i just assumed it
wasn't supposed to. I just read, however, that it does have a vacuum
switch, so I guess it was broken when i bought the car, since the
trunk switch seems to be on the same line and works fine.

Assuming i'm rigth, can anyone tell me where the gas flap vacuum
switch is located and how hard it is to replace.

Thanks very much.