Vintage Cars: Starter/solenoid trouble shooting, starter solenoid, selinoid

Question
Hey Ron, it's me again!  Getting sick of me yet? I want to start by saying thank you for helping me with the glow plug problem and for giving me Rusty's number.  Everything worked out fine there, and I even put new floor panels in the 300d and she is looking great.  A couple of nights ago, we had some pretty cold weather and in the morning she wouldn't even turn over, only made a "click" sound.  My first instinct was the battery, but the voltage read just fine (12 V) when measured.  A friend told me to try tapping the solenoid with a hammer, and this actually worked.  There's obviously a problem with the solenoid and or starter, but I'm not sure what it is exactly and how to narrow in on the problem.  I've heard that replacing either of these parts isn't always necessary, as the problems could stem from a large number of related, but seperate malfunctions.  Any ideas on where to start?  Thanks so much Ron!

Answer
Hey Cody
Tapping the starter is an old mechanics techique to get them to run. Actually what you are doing is tapping the starter gearing to move the brushes off a bad part of the armature.  It most certainly sounds like a new starter is in your future.  I would just take yours off and see if it can be rebuilt, a new selinoid always comes with a rebuid.  The item is common and does not need to be MB part.
Good Luck