Vacuum line confusion
 

I'm trying to sort out the vacuum lines on a 1984 300sd. Originally I was troubleshooting a shutoff problem.

Figured out that the brown line that is supposed to go to the shutoff valve was not actually hooked up to the shutoff valve. In the picture it was hooked up to the T where the golf tee now is. Its now hooked up to the shutoff valve and the car shuts off. Yay!

The questions I now have is, what should be where the tee is, and isn't something supposed to be hooked up to that empty spot on the white thing? (I just forgot the name of it).

On the T with the tee, one of the two remaining lines goes to the vacuum relay on top of the engine for the EGR, & the other goes into the cabin under the dash & just ends (open).

I've tried looking up the schematics but am just left more confused. None seem right for an '84 SD.

Thanks. That seems much better now.