My 84 300td has a horrible shake over 70mph, which is a bit hard for me to diagnose since I live almost an hour from the interstate... I have to drive out to closed course (or something like that)

None of my tires are missing their weights. The shake isn't really in the steering wheel, rather than in the whole body of the car, doesn't matter if I'm accelerating or in neutral.

Recently I replaced my giubos and center bearing/support. The previous mechanic put the driveshaft together 90 degrees out of alignment, so that vibration is gone now. But the horrible shake in the body is still present. Two years ago I replaced one axle with a napa reman, a couple weeks ago I replaced the other with a Duralast Gold. I'm not sure if the issue could be an axle or not.

I'm out of ideas here, any suggestions?

__________________
1984 300TD -- summer daily driver
Many others that aren't Mercedes...