GP & Rack Pin
 

As advised by PEH, I tested the glow plugs and replaced only the plug with a bad resistance reading. I also located and adjusted Rack Pin with no discernable effect. Does this mean that I need to replace the old (silver) Pin with a new (gold) Pin?

If your car wasn't having the shaking problem at idle when warm then you're alright. It doesn't hurt to replace it because the new one has a stronger spring in it, but once agian, if it ain't broke don't fix it :)

It shakes pretty good in gear, at a stop, when warm. Replaced bad GP today and start is much smoother. However, warm idle still a lot of vibe and no discernible relief with Rack Pin adjustment. May try new design (gold). So much to be addressed on this car that it's hard to focus on one step at a time.