Patience Grasshopper.
There is no such thing as an unanswerable question here. It might take a while for it to get answered but it will, if somebody wants to.
Both of my MB165's have a plan nut and no washer on the triple trees.
All of my MB200's have a chrome nut and a washer on the triple trees.
The washer looks more like a valve spring shim for a big block Ford or GM than it does a washer. Large ID and a small OD.
Doug