Since there has been no change in the amount or rate of vibration during the time owned, I would have to wonder if the previous owner had any driveshaft work done. Possible that the driveshaft wasn't marked, or may be off one or two teeth at the coupling. That would give you a vibration.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.