Doesn't seem likely but pull the breather tube and see what happens. Many people have reported extensive blow by on this board, but no one has ever mentioned that it is blowing back into the turbo and out the exhaust. I don't even understand how it could get back into the turbo and out the exhaust unless the oil seals were bad. It might get into the intake but then it would burn before it got out the exhuast.
You could also check for a turbo at a junkyard or on Ebay. My local pick and pull would sell one for less than $50.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13