The W115/W108/W109/W123/W116 cars all lock ONLY from the driver's door
since that is the only place there is a valve. All cars with a single
line system can be unlocked from either front door or the trunk.
The key will unlock the PS and trunk on the earlier cars, but will not
release the vac locks. There is a spring loaded override that will be
VERY stiff with lack of use.
I would suspect either the VIN got garbled or the lock set is not
original (or the VIN isn't -- check the one on the radiator support vs
the one on the door pillar!)
Peter
