I'd also take the tires off and roll them down the driveway, see if there is any sideways motion indicating internal issues even if they balance OK. Had this a long time ago, replaced everything, still had vibration. found out by accident when I rolled tire into the garage. It had a slight sideways motion every rotation. Its next rotation was into the trash.

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Hanno
'79 6.9 Sold (after 27 years)
'83 280SL, 5 spd.
'94 E320 Sdn. 5 spd conversion
'02 E320 Sdn.(on loan to mom!)
'87 300E (5 spd. conversion) Sold
'05 E500 Wagon