There is a configured chunck of rubber that is attached to the door check in a manner so as to allow the rubber to be slightly compressed just before the door is completley open and when the door is completely open. That rubber is kind of like a spring, if you will that "sets" the door in it's open position. The shock piece of rubber is something someone just rigged up. The piece of wood has nothing to do with the door check.
I believe those door checks are reproduced. You can probably find them available from several of the vendors.
Joe
