I'm still not convinced where the oil is going......
It's burnin', burnin', burnin'! Either that or there's some kid sucking it
out at night while you're sleeping. Seriously, oil in the vac lines could
be the source of the problem. You still haven't found any obvious signs of
oil anywhere on the engine or under the car? I don't think that your engine
is worn out!
I sure hope that you get to the bottom of this soon.
Kevin in Hillsboro OR
1983 300SD 284K miles, Ursula
PS. She hasn't been driven enough yet to check oil consumption.