No bomb damage - just trying to restore the steering to solid useable
condition on a sweet old car.

Front end work is pretty much beyond me.  I took it to one shop, they said
all it needed was the steering box adjusted.  It seemed to handle better
after they were finished but it still handled poorly in hi-speed
(65 mph) driving.  

I took it to an MB dealer - they tell me I need the upper A-arms and lower
strut joints.  They can do the work for me for a bit over $1000.  I'm
trying to get a handle on the reasonable value for this work before
calling other shops.....

Ball joints do wear out... especially the top one. You have to understand
that most 300D are exceeding 200,000 miles on the clock and by that time, at
least the upper control arm needs to be changed.

Upper control arm is very easy to replace... takes about 1 hour per side.
Lower arm is harder to change and alot of safety problems... plus you need
right tool to change this. Most likely the mechanic will remove the spring
to perform both job. You should consider changing your springs at this time
too.