Your turbo is shot, get it fixed. It's leaking oil into the exhaust
side, and it burns off when you accelerate. It will eventually make
such a smokescreen you will get ticketed for excessive smoke, but the
engine will run fine.
Your compression is a normal (lower than new, considerably above repair
limit), so any oil that goes down the intake will burn completely
unless you are burning more than three or four quarts to a tank of
fuel. Oil in the exhaust, on the other hand. always burns badly and
makes blue smoke.
Oily residue in the tailpipe is diagnostic.
You may want to check for excessive blowby (from the valve guides), but
most likely it's a blown turbo. This failure is pretty commonly
mistaken for low compression due to bad rods on the 603, especially the
3.5L version. Turbo is pretty cheap.
Peter
