Thank you all for your input- OK- update- So after close inspection under the car, the drive shaft center support has disintegrated leaving the drive shaft with about 1/2" of play on either side inside the center support. Looks like I am in for a fairly long repair job, and I will be replacing the center support and bearing, and at least one flexdisc (however they are both reasonable shape, its just a "while you are there" thing for me.).

Thanks for all your safety input, however fun fact: I drove 1,200mi with a loose drive shaft center support. W123 durability.

I will update this thread hopefully with some photos of the job, its gonna be a &#($ but will be nice when its finished.