The tool number Brian mentioned is the same used for the ML.
You won't need a seal for the dipstick tube cap, just the plastic lock to retain the cap once you are through. A 98 or 99 ML should have the drain plug on the torque converter. After that I wouldn't count on it. Again, the change to no drain plug seemed to have taken place about the time the shifter changed to Touchshift (model year 2000). You of course would want to change the seal on the trans pan and torque converter, if equipped with a drain plug, and of course the pan gasket.
I wouldn't be as sure as Brian in saying what type of head the crank pulley bolt has. I would assume everyone would want to verify what is needed before purchasing either tool anyways; no big deal and common sense.
Also Col, most cars don't have a drain for the torque converter. Mercedes has been very unusual in providing this. I guess they no longer feel it's neccesary due to having no recommended fluid change interval. On other cars you either feel 'good" about just changing what is in the trans case only, or you do a flushing procedure instead of a normal fluid change as we have grown accustommed to on MB's.