strange chassis vibration

[thomcat]

1976 300d
It feels like a tire with broken cords and it wanders a bit on uneven pavement .My tires were pretty dry rotted so I replaced all 4, but no change
After checking steering gear play and wheel beering etc i found some parts arent as snug as new but nothing that wouldnt be able to be aligned or could account for this.
Then I noticed that the four bushings that mount the engine cradle and suspension to the body are crumbling and I could jerk on the front wheel hard enough to see movment in these bushings. what are they called? (my manual still hasnt arrived) anybody know a cheap source?
does this sound like a likely culprit?
I am goint to replace them regardless. but didnt know if I should be looking elseware as well
thanks for your time Thom