If this car is a "keeper", then I would replace the parts with new German made stuff. If your steering box has any issues after adjustment, you are inviting problems by buying someone else's old stuff UNLESS you can buy one which truly has a documented 100K on the clock or less. Your absolute best bet is to get Martureo to rebuild your box. He's well under $200 bucks. You can ship your box for under $20 USPS flat rate by removing he Pittman Arm with shipping back to you the same.

Again, time and aggravation is something to consider. If you have limited time and/or money, spending it twice down the road is not going to be helping you now or in the future. MB German new parts are surprising cheap compared to other parts for newer models. Time to replace is generally not horrible, and there are a zillion posts plus the FSM is all over the net. I have learned over the past few years that it makes almost no sense to replace this "one" part when all the others are probably just as old and on the verge ... versus replacing everything I can in a system.

Just my .02 cents.