If you can find a counterbore the right size then installing a Helicoil would be easier than changing the base assy. Of course working on that will give you a crick in the neck the way its situated high up under the car.

One thing I hate about the 220 (gasser) I own is changing oil, the dreaded filter cannister on 115's is a bad deal.
I had one experience with the long bolt that holds the housing on, it was real loose when I went to change oil last year, I could unscew it by hand, yet it never leaked around the filter for some reason so I consider myself lucky as it had been over a year since the last oil change (at the time I didn't drive it very much).

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!